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Strong Magnetic-Field TreatmentStrengthens NiAl-Cr(Mo)-Hf Alloy

NiAl-Cr(Mo)-Hf alloys offer significantpotential for use as high-temperature,lightweight structural materials. Theyshow good strength at high temperatures,good oxidation resistance, and high wearresistance. These alloys, however, are verybrittle and have low tensile strengths, par-ticularly at room temperature. Variousefforts to improve the ductility of thesealloys have been marginally successful. Amethod has now been reported to signifi-cantly improve the ductility and bendingstrength of the alloy. By subjecting a NiAl-Cr(Mo)-Hf alloy to a high magnetic field,G.J. Ma and W.L. Zhou of the DalianUniversity of Technology, J.T. Guo of theShengyang Institute of Materials Research,and their co-workers have increased thebending strength of the alloy by 75%.

As reported in the February 2005 issueof the Journal of Materials Research (p. 295;DOI: 10.1557/JMR.2005.0047), rectangular

cross-sectional NiAl-Cr(Mo)-Hf alloyspecimens, formed from a nominal com-position of Ni-33Al-28Cr-5.5Mo-0.5Hf,were heated to 900ºC under a 10 T homo-

geneous high magnetic field. Upon cool-ing to room temperature, the bendingstrength of the specimens was character-ized using the three-point bending

Figure 1. Electron probe microanalysis of the microstructures (a) without magnetic-field treat-ment, in which N-2 represents the NiAl phase and N-3 represents the Cr(Mo) phase; and(b) after magnetic-field treatment, in which T-2 represents the NiAl phase and T-3 representsthe Cr(Mo) phase. Reproduced with permission from the Journal of Materials Research 20 (2)(February 2005), p. 295; DOI: 10.1557/JMR.2005.0047. © 2005 Materials Research Society.

a b

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a b

c

Figure 1. ORTEP drawing (50% A: 0.5 –y, x – 0.5, z – 0.25) of a single 41 helix inComplex IV (a). Top (b) and side (c)views of two adjacent helical chains inspace-filling modes. ORTEP stands forOak Ridge thermal-ellipsoid plot pro-gram. Reproduced with permissionfrom Chemical Communications (2005),p. 1258; DOI: 10.1039/b416095a. © 2005 Royal Society of Chemistry.

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method. While the average bendingstrength of the untreated alloy was 245MPa, the average bending strength of thealloy treated with the magnetic field was430 MPa, roughly a 75% increase. Theelastic modulus remained unchanged.Scanning electron microscopy observa-tions of the fracture surfaces of the treatedspecimens showed typical ductile fracturecharacteristics. The fracture surfaces ofthe untreated specimens clearly showedbrittle characteristics with microcracks,the researchers reported.

In order to understand the underlyingmechanism, C.W. Wu in the Departmentof Mechanical Engineering at Dalian saidthat the research group performed elec-tron probe microanalysis on the untreatedand treated samples. The untreated alloyconsists of NiAl, Cr(Mo), and Heuslerphases. These do not change when thealloy is heated to 900ºC. In the magnetic-field-treated samples, the Heusler phasesat the NiAl/Cr(Mo) grain boundarieswere partly dissolved into the NiAl andCr(Mo) phases. In addition, small Heuslerphase particles at the Cr(Mo) and matrixphase interfaces partially dissolved intothe NiAl matrix (see Figure 1). Theresearchers speculated that the dissolu-tion of the Heusler phase due to the high-magnetic-field treatment contributed tothe improvement in bending strength andductility of the alloy. The exact mecha-nism, however, remains unclear.

GOPAL RAO

Metalorganic Building BlockEnables Synthesis of FourSupramolecular Isomers

While supramolecular isomerism iswidely encountered in the field of crystalengineering, the majority of these thathave been reported require a co-existenceof different guest components for pro-duction. An elementary system of supra-molecular isomers that has been encoun-tered is the zero-dimensional ring-like,one-dimensional zigzag, and helicalchains that can be derived from a stoi-chiometry of 1:1 metal/ligand molarratio. Now, X.-M. Chen and colleaguesfrom Sun Yat-Sen University in Chinahave fabricated low-dimensional supra-molecular isomerism (chairs, zippers, andchains) of 0D/1D coordination polymerswithout the use of guest components.

By using a binary Cu+1 triazolate[Cu+1(2-Hpytz)]x (2-Hpytz = 3,5-di-(2-pyridyl)-1,2,4-triazolate) pre-designed,metalorganic building block, the research-ers isolated four types of air-stable crys-tals of different colors and/or shapes.Crystallographic studies revealed the stoi-chiometry of 1:1 (metal/ligand) for all

complexes isolated. The researchers’ find-ings were reported in the March 1 issue ofChemical Communications (p. 1258; DOI:10.1039/b416095a).

The different complexes were synthe-sized based on the different conformationsof the coordinating ligands. Complex Iwas a red polyhedral crystal that pos-sessed a centrosymmetrical, chair-liketetrameric superstructure. The researchersattributed this superstructure to the cis-cisand cis-trans 2-Hpytz ligand conformations.Complex II (with the conformation ofHpytz ligand, cis-trans, and half a cis-cis)was a red column crystal that has a highlydistorted tetrahedral environment thatproduced a zipper-like double-chainsuperstructure. Complex III (with theconformation of pytz ligand, one cis-trans,and a distorted tetrahedral Cu+1 metalcenter) was an orange column crystal thatis centrosymmetric, which gave rise toanti-parallel, aligned, polar zigzag chains,the researchers said.

Complex IV (see Figure 1) was anorange needle-like crystal that gave riseto a homochiral structure with an anti-parallel, aligned, single-stranded 41 helix,which is rare, the researchers said. Thiscomplex was synthesized by varying thereaction times and conditions. Theresearchers said that this system representsthe first example of low-dimensional,supramolecular isomerism in coordinationpolymers and gives rise to controlled crys-tallization of individual isomers.

LARKEN E. EULISS

Wavelength Multiplexing ofMicrosphere Resonators Used toCharacterize Nanolayers

Biosensors are widely used in clinicaland military applications as well as for thecharacterization of biomolecular interac-tions important in drug discovery. Whiletraditional optics employ nanolayers madefrom inorganic insulators, semiconductors,and metals, the emerging field of biopho-tonics employs DNA, proteins, lipids, andhydrogels in soft condensed biofunctionallayers formed at aqueous–solid interfaces.Recently, S. Arnold and co-researchersfrom Polytechnic University in New Yorkhave developed a non-invasive method tooptically characterize bioactive nanolayersformed in situ on a silica microsphere.

As reported in the March 1 issue ofOptics Letters (p. 510), the research teamdeveloped an appropriate theory, validat-ed it experimentally, and then demon-strated their method’s utility by opticallycharacterizing a biophysically relevanthydrogel. Focusing on the theoreticaleffect that a nanolayer has on a micro-sphere’s whispering-gallery modes(WGMs), the researchers applied pertur-bation theory to transform the electric-field equations for the transverse electricWGMs to make the problem analogous tothe solution of the Schrödinger equationwith an appropriate effective potential.The optical transmission spectra of theWGMs have resonances that are per-turbed by the addition of nanolayers ofmaterial. By judiciously choosing twowavelengths, λ1 and λ2 (760 nm and 1310nm, respectively), the researchers foundthat the ratio S of the fractional shifts in theresonances of the WGM wavelengths hasthe limit of λ1/λ2 (0.58, in this case) for athick layer and a limit approaching unityfor an ultrathin layer. In addition, usingtwo equations derived by the researchers,both the layer thickness and the opticaldielectric constant can be independentlydetermined from the measurements of thewavelength shifts of the WGMs.

The researchers conducted two experi-ments to test these limits. In the first, as amonolayer of bovine serum albumin (~3nm thick) was formed on a silica micro-sphere, monitoring of the resonancesassociated with the two wavelengthsshowed that each shifted about the sameamount, S = 1, consistent with the theoryfor a thin layer on the microsphere. In thesecond test case, the researchers injectedNaCl into the water surrounding amicrosphere and incrementally increasedthe salt concentration by 0.1 M. A plot ofthe resonance shift at λ1 versus the reso-nance shift of λ2 displayed a slope of 0.54,consistent with that predicted for the for-

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mation of a thick layer around the microsphere. The researchers saidthat both limiting tests agree reasonably with theory.

The researchers then characterized a nanolayer composed ofpoly-L-lysine hydrogel, which, due to its very high charge, readilyadsorbs negatively charged biomolecules. Poly-L-lysine hydrogelnanolayers are also difficult to characterize using other methodsbecause it forms such thin layers with low contrast to water. Theresearchers observed a very small resonance shift, which their theo-ry indicates corresponds to a layer thickness of 110 nm and anexcess refractive index of 0.0012. The researchers said that as aresult of their method, “the WGM resonator goes beyond its origi-nal promise as a biosensor.” In addition, the researchers anticipatethat real-time measurement of S will reveal morphology changesconcomitant with increases in layer density. Furthermore, Arnoldand his co-researchers said that an alternate formulation of theirtheory applied to nonspherical particles “shows promise for look-ing at heterogeneous structures such as adsorbed bacteria.”

STEVEN TROHALAKI

Metalorganic Gel Used for Porous Organic Polymer Template

Coordination polymers where metal centers are linked by organicbridging ligands represent novel materials with potentially usefulporosity and inclusion properties. Much of the research on this class ofmaterials has, however, focused on studying single crystals of thesematerials to understand the molecular basis for their formation andproperties. Polymer gels—which potentially have interesting proper-ties in catalysis, sensing, and as responsive materials—have been farless studied. In the March 28 issue of Chemical Communications (DOI:10.1039/b418554d), Q. Wei and S.L. James from the Queen’sUniversity of Belfast in Northern Ireland report the reaction of ironnitrate and 1,3,5-benzenetricarboxylic acid in ethanol to give a metal-organic gel with a solvent content of 95–98% by weight.

The researchers propose that coordination polymer particles areformed by rapid cross-linking polymerization between Fe3+ and thebenzenetricarboxylic acid and that these particles are further cross-linked to provide macropores that trap solvent molecules. The gelcan be formed in the presence of organic monomers, which can betrapped in the cavities and polymerized to form porous imprints ofthe metalorganic gel. Wei and James demonstrate this forpoly(methyl methacrylate) (PMMA) by polymerizing methylmethacrylate in the gel cavities and dissolving the gel framework inhydrochloric acid. The resulting PMMA imprint contains disorderedpores with a size range of 1–10 µm.

James said that the major advantage of this technique is that it is astraightforward and inexpensive route to templating porous organicpolymers, which have potential applications in supports and separa-tions. The presence of metalorganic particles within the polymermatrix suggests that other interesting magnetic and responsive prop-erties may be observable in these materials, the researchers said.

SARBAJIT BANERJEE

Tungsten Nanoparticles Embedded in Silica Enhance Nonvolatile Memory

Many consumer electronic products use nonvolatile memorydevices in their operation. One such device is electrically erasableand programmable read-only memory (EEPROM), which uses afloating gate structure. In the drive to develop memories with lowerpower consumption and faster erase/write cycles, researchers havebegun to incorporate nanocrystals into their EEPROMs in order toimprove performance. Recently, T.C. Chang of the National SunYat-Sen University, P.T. Liu of the National Chiao Tung University,and their colleagues demonstrated that replacing the floating gate inEEPROMs with tungsten nanocrystals in a silica matrix reduces theoperating voltage and increases endurance. Using nanoparticles in

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266 MRS BULLETIN • VOLUME 30 • APRIL 2005

the floating gate makes the structure moretolerant to defects in the tunnel oxide andtherefore reduces leakage. This permitsthe use of thinner tunnel oxides, which inturn reduces the operating voltage,improves endurance and retention, andincreases the write/erase rate.

To fabricate their devices, the researcherstook advantage of the fact that tungsten sili-cide on SiO2 forms elemental tungstenwhen thermally oxidized. As described inthe March issue of Electrochemical and Solid-State Letters (p. G71), the team began bygrowing a 4.5 nm tunnel oxide on siliconsubstrates, followed by sputter depositionof 8 nm of W5Si3 for the floating gate and 10nm of amorphous silicon. A thermal oxida-tion step formed the control oxide and theelemental W in the SiO2 matrix. The W par-ticles had an average diameter of 4.5 nmand an areal density of 3.7 × 1011 cm–2.Fourier transform infrared spectroscopyanalysis showed that elemental tungstenwas clearly present, with little or no tung-sten oxide formation.

The researchers used capacitance–volt-age measurements to demonstrate the elec-tron charging effect of their W particles. Abidirectional voltage sweep from 3 V to–4 V and back to 3 V yielded a shift in thethreshold voltage ∆Vt of 0.95 V, which issufficient for binary switching. Theresearchers found that there was no appre-ciable decrease in ∆Vt until after 106 cyclesand in fact, after 109 cycles, ∆Vt had onlydropped to 0.71 V.

The operating characteristics of the Wnanoparticle EEPROMs represent animprovement over both the high 7 Voperating voltage of conventional floatinggate devices and the rapid drop-off seenin the endurance of other nanoparticledevices. In addition, this silicide tech-nique is easily integrated with existingsemiconductor technology, making the Wnanocrystal devices viable competitors toconventional EEPROMs.

AMANDA GIERMANN

Transparent Hydroxyapatite with High Crystal OrientationProduced by Pulsed ElectricCurrent Sintering

Hydroxyapatite [Ca10(PO4)6(OH), HAp]is a major mineral component found inbones and teeth. As a biomaterial, it aidsthe growth and development of bones andteeth by providing attachment sites for newcells. HAp has a hexagonal crystal structureand there is a large difference in cell attach-ment between the a plane and the c plane.Sintered dense HAp bodies with a highdegree of crystal orientation are useful forculturing cells and as scaffolds for theregeneration of bones and teeth.

In the January issue of the Journal ofAmerican Ceramic Society (p. 243; DOI:10.1111/j.1551-2916.2004.00041.x),researchers Yujiro Watanabe of HoseiUniversity, Japan, and Toshiyuki Ikomaof the National Institute for MaterialsScience, Japan, and colleagues reported asintering process for producing dense,transparent, and highly oriented crys-talline HAp bodies.

The researchers first prepared the HAppowder by reacting Ca(OH)2 with H3PO4

solution, followed by spray drying andthen calcining at 800°C for 3 h. Sinteringof the HAp sample was carried out bypulsed electric current sintering (PECS) ina spark plasma sintering (SPS) system. Inthe PECS process, powder particles arecharged with electrical energy and a highpressure is applied on the sample.

During the sintering of HAp, the samplewas pressed uniaxially at 50 MPa in vacu-um. The sintering temperature was elevat-ed at a rate of 50°C/min to 1200°C. Aftermaintaining the temperature for 10 min,the sample was slowly cooled to 600°C ata rate of 5°C/min. The electric currentwas then stopped, the pressure wasreleased, and the sample was cooled toroom temperature.

The resulting bulk sample has highoptical transmittance at wavelengthsabove 700 nm to at least 1100 nm (i.e.,>70% for a 1-mm-thick sample), and adensity >99.7% of the theoretical value.As for the crystal orientation, theresearchers concluded from x-ray diffrac-tion measurements taken perpendicularand parallel to the direction of the pres-sure that there is a very significant crystalorientation on the a, b, and c planes. The cplane is aligned parallel to the pressuredirection, while the a and b planes arealigned perpendicular to the pressuredirection. Orientation indexes of the a andb planes are much higher than those ofsamples obtained with other processes.

SHIMING WU

LaPO4:Eu3+ Nanowires LuminesceMore Efficiently than Dots

One-dimensional LaPO4:Eu3+ nano-wires luminesce more efficiently thanzero-dimensional, spherical LaPO4:Eu3+

nanoparticles, said Hongwei Song andco-workers from the Chinese Academy ofSciences. As reported in the March 1issue of Optics Letters (p. 483), theresearchers studied the luminescentproperties of low-dimensional LaPO4

doped with rare-earth Eu in order to bet-ter understand the fundamental physicsof this new condensed-matter system.With the technological drive towardsmaller and novel devices, LaPO4 is

appropriately studied as it is used in fluo-rescent lamps, cathode ray tubes, andplasma display panels.

The research team reported that the Euatoms partially filled f orbitals, whichcarry magnetic moments. In addition,Eu3+ ions are sensitive activators for usein the study of local symmetry. Theresearchers used this property of Eu3+ tostudy the structural differences betweennanowires, nanoparticles, micron-sizedpowders, and micron-sized rods.

The LaPO4:Eu nanowires, nanoparticles,micropowders, and microrods were pre-pared by a wet chemical method. The col-loidal nanoparticles and micropowderswere basic and the nanowires and micro-rods were acid. The diameter of thenanoparticles and nanowires ranged from10–20 nm, whereas the length of nano-wires ranged by several hundred nano-meters. The diameters of micropowdersranged over 1–2 µm. The diameters andlengths of the microrods were ~200 nmand 1–2 µm, respectively. X-ray diffractionpatterns revealed that the crystal struc-tures of all of the samples belong to themonoclinic monazite type. Time-resolvedemission spectra and high-resolutiontransmission electron micrograph imagesshow that the Eu3+ ions occupy two sitesin the nanowires as well as the microrods,but not in the nanoparticles or the micro-powders. The researchers attributed thisresult to a degeneration of the crystal fieldin the micropowders. They also concludedthat the observed higher radiative rate fornanowires, as compared with the nano-particles, micropowders, and microrods,was due to the “variation of the electronic–magnetic dipole field caused by shapeanisotropy.”

VIVEK RANJAN

Raman Measurements in SiliconNanowires Reveal the DiameterDependence of PhononConfinement

Phonon confinement in a small nano-system leads to an asymmetric broadeningof the Raman bands. Recently, P.C. Eklundfrom the Pennsylvania State University,G.U. Sumanasekera from the Universityof Louisville, and their co-workers deter-mined the evolution of phonon confine-ment with wire diameter of long, crys-talline Si nanowires using the Ramanmicroprobe method.

As reported in the March 1 issue of Nano-Letters (p. 409; DOI: 10.1021/nl0486259), theresearchers prepared Si nanowires bypulsed Nd:YAG laser vaporization of a Sitarget containing ~10 at.% Fe. The wiregrowth process occurs through thevapor–liquid–solid mechanism in which a

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Fe/Si nanoparticle acts as a “seed” and theSi filaments grow from the Fe/Si nanopar-ticle surface. This approach producedwires with a distribution of diametersranging from 8–40 nm. In order to producesmaller-diameter wires, the researchersdeveloped a post-synthesis approach.They used oxidation at elevated tempera-ture to diffuse oxygen radially inward andshrink the Si crystalline core. Fractionswere then separated according to thewire diameter using centrifugal separa-tion. Using this method, the researchersproduced a series of four crystalline Sinanowire samples whose most probablediameters were 4.5 ± 0.2 nm, 6.5 ± 0.3 nm,9.5 ± 0.3 nm, and 23.1 ± 0.7 nm. Theresearchers probed the phonon bands inthese nanowires using Raman spectros-copy at low enough laser intensity thattemperature broadening was not a factor.Comparison of the Raman spectra ofthese Si nanowires showed that withdecreasing diameter, the first-orderRaman band at ~520 cm–1 develops anoticeable asymmetry to lower frequen-cy, and the peak position downshifts.

The researchers analyzed their resultsbased on an asymmetric line-shape modeldeveloped by Richter with an adjustableparameter (α) added to the theory thatdefines the width of the Gaussian phonon-confinement function. The researchersfound that this parameter is not sensitiveto diameter over the 4–25 nm range if theytook into account the measured diameterdistribution. This result is contradictory tothe large range of reported α values. Whileattributing the difference to a variety ofunknown conditions, the researchers saidthat the thickness and nature of the oxidecoating on the wire might also impact thephonon confinement. That is, they said, thephonon in the crystalline core of thenanowire has to decay into phonons in theoxide shell. Therefore, the researchers sug-gested future experiments on hydrogen-terminated Si nanowires to see how hydro-gen termination affects the value of theconfinement parameter.

TAO XU

Bulk Metallic Glass Foam Achieves High Ductility

Metallic foams are currently used asultralight structural materials. Bulk metal-lic glasses (BMGs) show exceptionalstrength and elasticity, in addition to otherfavorable properties, rendering them alsouseful for structural applications andpotentially for biocompatible implants.A.H. Brothers and D.C. Dunand of North-western University considered, then,whether BMG foams offer unique oppor-tunities in engineering structures or bio-

medical implants. They have found thatVit106 (Zr57Nb5Cu15.4Ni12.6Al10) foamshows compressive properties not unlikeductile aluminum foam, despite a lack ofductility in monolithic Vit106. Further-more, Vit106 contains neither preciousmetals nor toxic beryllium, and showsbiocompatibility.

As reported in the February 18 issue ofAdvanced Materials (p. 484, DOI: 10.1002/adma.200400897), the researchers pro-duced samples by crushing optical-gradeBaF2 and sieving it to produce and select215–220 µm particles. These were thenpacked into graphite crucibles and sin-tered at 1250°C for 10 h under high vacu-um. The 7-mm-diameter patterns werethen placed in stainless steel crucibles andvacuum-dried at 300°C for 30 min. Vit106charges were then combined with the BaF2

patterns in preheated crucibles and melt-ed. High-pressure argon gas was appliedto the Vit106 surface to drive it into theBaF2 pattern. After cooling, the Vit106/BaF2 composite was ground to a desiredsize and the BaF2 was leached out usingnitric acid. Scanning electron microscopeimages of Vit106 foams of 4.5 mm diame-ter and 8.7 mm height show 78% openporosity with pore sizes of 212–250 µm.The thickness of all Vit106 struts is wellbelow 1 mm, where high bending ductili-ty is expected. X-ray diffraction shows thatno crystalline phases were present in thefoam. The researchers concluded thatBMG foams can achieve high compressiveductility through strut bending, in sharpcontrast to the brittle compressive behav-ior of BMG in monolithic form.

VIVEK RANJAN

Materials Issues in Solid Free-FormingSymposium LL brought together discussions addressing important issues relat-

ed to free-forming and other parallel processing methods for advanced materials.The symposium opened with a special symposium address titled “ElectrosprayingWings of Molecular Elephants” by John Fenn, 2002 Nobel Laureate in chemistry.The presentation elucidated the electrospray technique and the significant advan-tage in the use for weighting large biomolecules. Several sessions followed, withinvited papers from a host of eminent scientists from around the world. The firstsession covered the broad field of solid free-forming, with M. Edirisinghe (QueenMary, Univ. of London), B. Derby (Univ. of Manchester), A. Safari (Rutgers), andL. Iuliano (Univ. Modena, Italy) presenting talks on jet-based and other advancedmaterials-forming methods at both the nano- and micrometer scales. The follow-ing session covered 3D fabrication and applications (J. Beaman, Univ. of Texas; E.Sachs, MIT; Y. Gogotsi et al., Drexel). The second day started with a session onprocessing and fabrication of advanced materials (G. Babini and L. Settineri,Politecnico di Torino, Italy). The final session addressed electrohydrodynamicatomization and applications (J. De la Mora, Yale; K.-L. Choy, Univ. ofNottingham; M. Brenner, Harvard, and I. Loscertales, Univ. Malaga).

Symposium Support: ARL and Queen Mary, Univ. of London.

CorrectionsMRS Bulletin misprinted the sponsors of Symposium LL in the report on the

2004 Materials Research Society Fall Meeting (MRS Bulletin 30 [3] [March 2005]p. 239). Support to Symposium LL was given by the Army Research Office(United States of America) and the Engineering and Physical Sciences ResearchCouncil (United Kingdom). Following is the corrected report.

Materials Issues in Solid Free-FormingSymposium LL brought together discussions addressing important issues related

to free-forming and other parallel processing methods for advanced materials. Thesymposium opened with a special address titled “Electrospraying Wings ofMolecular Elephants” by John Fenn (Virginia Commonwealth Univ.), 2002 NobelLaureate in Chemistry. The presentation elucidated the electrospray technique and thesignificant advantage in the use for weighing large biomolecules. Several sessions fol-lowed, with invited papers from a host of eminent scientists from around the world.The first session covered the broad field of solid free-forming, with M. Edirisinghe(Queen Mary, Univ. of London), B. Derby (Univ. of Manchester and UMIST), A. Safari(Rutgers), and L. Iuliano (Politecnico di Torino) presenting talks on jet-based andother advanced materials-forming methods at both the nano- and micrometer scales.The following session covered 3D fabrication and applications (J. Beaman, Univ. ofTexas; E. Sachs, MIT;Y. Gogotsi et al., Drexel).The second day started witha session on processing andfabrication of advancedmaterials (G. Babini andL. Settineri, Politecnico diTorino). The final sessionaddressed electrohydrody-namic atomization andapplications (J. De laMora, Yale; K.L. Choy,Univ. of Nott ingham;M. Brenner, Harvard,and I. Loscertales, Univ. ofMalaga).

Symposium Support: ArmyResearch Office (United States ofAmerica) and the Engineeringand Physical Sciences ResearchCouncil (United Kingdom).

Nobel Laureate John Fenn (left) with SuwanJayasinghe, lead symposium organizer.

For more research news on Materials Science, access the Materials Research Society Web site: www.mrs.org/connect ions

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ous novel biomate-rials; C.N.R. Rao(Jawaharlal NehruCentre, India), for hissustained record ofscientific accomplish-ments in solid-stateand materials chem-istry; and GeorgeWhitesides (Harvard University, USA)for having bridged the fields of chem-istry, chemical engineering, and biologyto new heights through the develop-ment of novel functional materials andsystems.

To foster the next generation of schol-ars, each laureate is to donate $15,000 asa scholarship to an outstanding doctoralcandidate in materials science.

The awards will be presented at aceremony to be held on May 23, 2005,at Tel Aviv University. The prize, estab-lished in 2001 and named after interna-tional businessman and philanthropist

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268 MRS BULLETIN • VOLUME 30 • APRIL 2005

News of MRS Members/Materials Researchers

This year, the Dan David Prize hasgiven a $1 million award for achieve-ments in materials science, recognizingresearchers’ outstanding scientific im-pact on the future.

Headquartered at Tel Aviv Univer-sity, Israel, the Dan David Prize annual-ly awards three prizes for achievementshaving an outstanding scientific, techno-logical, cultural, or social impact on theworld. Each year, one field is chosen foreach of three time dimensions—past,present, and future. The laureates for agiven year are chosen from these fields.

For 2005, materials science was cho-sen to represent the future time dimen-sion. Following a meeting of its distin-guished Board at the University of LaSorbonne in Paris, the Dan David Prizeannounced three award recipients inthis area: Robert Langer (MassachusettsInstitute of Technology, USA) for havingpioneered the development of tissueengineering and the creation of numer-

Dan David, is funded by the Dan DavidFoundation. David, inventor of auto-matic photo booths, is president ofPhoto Me International.

The Dan David Prize recognizeswork in different fields each year. Onthe announcement of the 2005 recipi-ents, David said, “This year, the win-ners of the Dan David Prize once againdemonstrate exceptional accomplish-ment…. In the field of materials science,the Dan David Prize has recognized theexceptional contribution of scientistswhose pioneering research offers abrighter future.”

semiconductorsand liquid-metals.”

The L’Oréal–UNESCO fellow-ship program,founded to encour-age young womenresearchers in thelife sciences, also branched out to otherfields this year. Among the 15 fellowsnamed is polymer scientist KetsiriKueseng (Walailak University,Thailand), for her work on the water-and oil-repellency of Thai silk. Kuesenghas been reported missing since thetsunami of December 2004.

The awards were presented to theL’Oréal–UNESCO laureates on March 3by Koïchiro Matsuura, UNESCO direc-tor-general, and Lindsay Owen-Jones,chair and CEO of L’Oréal. NicoleAmeline, French minister for parity andequality in the workplace, participated inthe ceremony in her capacity as presi-dent of the Honorary Committee.

Pierre-Gilles de Gennes, 1991 NobelLaureate in physics, presided over theevening’s events in the presence of themembers of the international jury andChristian de Duve, founding presidentof the awards and 1974 Nobel Laureatein medicine.

Belita Koiller

Myriam P. Sarachik Fumiko Yonezawa

The L’Oréal–UNESCO for Women inScience Award has awarded $100,000prizes to each of five materials scientistsfrom five continents—Africa, Asia-Pacific, Europe, Latin America, andNorth America. According to theL’Oréal–UNESCO partnership, the con-tribution of women in science is under-represented. One of the ambitions of theL’Oréal–UNESCO Awards is to helpbridge this gap and bring internationalrecognition to these exceptional scientists.

The 2005 awards go to Zohra BenLakhdar (University of Tunis, Tunisia),“for her experiments and models ininfrared light spectroscopy and itsapplications to pollution detection andmedicine”; Belita Koiller (FederalUniversity of Rio de Janeiro, Brazil),“for her innovative theoretical researchon electrons in disordered materialssuch as glass”; Dominique Langevin(University of Paris-Sud, France), “forher fundamental investigations of deter-gents, emulsions, and foams”; MyriamP. Sarachik (City College of New York,USA), “for important experiments onelectrical conduction and the transitionbetween metals and insulators”; andFumiko Yonezawa (Keio University,Japan), “for her pioneering theory andcomputer simulations of amorphous

“I am interested by materials sci-ence,” said de Gennes, “because thisfield does more than respond to a need;it creates new possibilities and, in termsof changing people’s lives, it is anessential discipline.”

The L’Oréal–UNESCO for Women inScience Awards, created in 1998, recog-nize the work of materials scientists forthe first time this year and will continueto recognize materials scientists everytwo years.

Zohra Ben Lakhdar Dominique Langevin

C.N.R. Rao George WhitesidesRobert Langer

Dan David Prize Recognizes Materials Scientists’ Impact on the Future

L’Oréal–UNESCO Award Promotes Women of Materials Science

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