Traveling solvent floating zone growth technique (TSFZ)

1. Mixing and calcinning of the starting materials

2. Isostatic pressing and sintering to a rod

3. Premelting of the sintered rod

4. Molten zone formed by infrared heat, focused by ellipsoidal mirrors

5. Crystal growth by traveling of the molten zone

Insight view of the infraredimage furnace

Feed rod

Molten zone

Ellipsoidal mirror

Halogen lamp

Crystal

Seed rod

Quartz tube

Controlled atmosphere

Lattice constants of Na CoOx 2

0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0

2.820

2.840

a (Å

)

c (Å

)

2.860O3 NaCoO2 P2 Na CoO20.7

2.880

2.900

2.800 10

11

12

13

14P2 O3

15

16

Co-O-Na diagram under 1 bar O pressure 2

0.75 1.0 X

800

700

600

0.5

T (°C)

Revised phase diagram for superconducting Na CoO ·1.3H O and x 2 2non-superconducting Na CoOx 2

0.6 0.7

x in Na CoOx 2x in Na CoO 1.3H Ox 2 2

0.8 0.9 10

5

T (

K)

N

T (

K)

c 10

15

20

25

0.4

G. Baskaran,PRL 91, 097003 (2003)

R.E. Schaak, et al.,Nature 424, 527 (2003)

M.L. Foo, et al., PRL 92, 24700 (2004)D.P. Chen, et al., PRB 90, 024506 (2004)H.W. Zandbergen, et al., PRB 90, 024101 (2004)J. Sugiyama, et al., PRL 92, 017602 (2004)

paramagneticmetal

Curie-Weissmetal enhanced

thermo power

MITT =53Kc

0.50.3

CO?

0.21

2

3

4

5Na order

T >> 250 Kc

C-SDW

IC-SDW

AFSC

CO

Na CoO0.75 2

LiFePO4

Zr Y O0.9 0.1 2

SrLaFe7

TiO2

Single crystal ingots

Sin

gle

crys

tal

seed

Gro

wth

dir

ecti

on

f 6 mm

f 6 m

m

f 8 m

m

f10 m

m

f 8 m

m

Crystals grown:

Bi Sr Ca Cu O (n=1, 2, 3), 2 2 n-1 n 2n+4+d (Sr, Ca) FeO , Ln CuO (Ln: La, Nd), 3-d2 4 Na CoO , LaMnO , Zr Y Ox 2 3 0.9 0.1 2, LiFePO : Mg, Zr, Si, Al, etc.4

Characterization of Na CoO crystals grown by TSFZx 2

Infrared image furnaces

X