11

Effects of AnnealingEffects of Annealing

• SEM surface morphology SEM surface morphology of porous alumina of porous alumina substrates sputtered with substrates sputtered with 20 nm Ni. 20 nm Ni. – (a) As sputtered smooth (a) As sputtered smooth

surface before annealing. surface before annealing. – (b) After annealing at 500(b) After annealing at 500ooC C

under Hunder H22 for two hours. for two hours.

– The continuous nickel thin The continuous nickel thin film transformed to film transformed to uniformly distributed nano-uniformly distributed nano-sized particles. sized particles.

(a)

(b)

22

Effects of Annealing (cont.)Effects of Annealing (cont.)(c) (d)

(e)

(c), (d) CNTs grown without annealing(e) CNTs grown after annealing