THE RESISTIVITY OF THE AMORPHOUS Fe1-xBx FILMS

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THE RESISTIVITY OF THE AMORPHOUS Fe1-xBx FILMS

T. Stobiecki, H. Hoffmann

To cite this version:

T. Stobiecki, H. Hoffmann. THE RESISTIVITY OF THE AMORPHOUS Fe1-xBx FILMS. Journal

de Physique Colloques, 1980, 41 (C8), pp.C8-485-C8-488. �10.1051/jphyscol:19808121�. �jpa-00220218�

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JOURNAL DE PHYSIQUE CoZZoque C8, suppZ6ment au n 0 8 , Tome 41, a o 6 t 1980, page C8-485

THE RESISTIVITY OF THE AMORPHOUS

Fel-,B,

FILMS

T. ~ t o b i e c k i ' and H. Hoffmann

J n s t i t u t e ftir Angewandte P h y s i k , U n i v e r s i t i i t Regensburg, 8400 Regensburg, R.F.A.

S o l i d S t a t e P h y s i c s Department Academy o f Mining and MetalZurgy, 30-059 Krakdw, aZ. MickiewCcza 30, Poland.

T h i s w o r k p r e s e n t s a s y s t e m a t i c i n w e s t - , o f c h a n g e s o f

?

^{a n d}^TCRw e r e much h i g h e r $ i g a t i o n o f e l e c t r i c a l r e s i s t i v i t y i n t h i n

f i l m s o f Fel,xBx i n w i d e r a n g e o f c o n c e n - t r a t i z n x u p t o x = 0 . 7 0

,

S a m p l e s w e r e p r e p a r e d b y RF s F u t t e r i n g t e c h n i q u e d e - s c r i b e d i r : p a p e r

[?I .

A m o r p h o u s s t a t e e x i s t s f o r C.12,< x ( 0.70 w h i c h was t e s t e d b y e l e c t r o n d i f f r a c t i o n m i c r o s c o p y

[zJ.

T h e f i l m c o m p o s i t i o n w a s d e t e r m i n e d b y m i c r o p r o b e a n d A u g e r a n a l y s i s w i t h a c c u r a c y o f 5 a t o m i c p e r c e n t o f 8.

T h e r e s i s t i v i t y w a s m e a s u r e d b y f o u r - p r o - be n a t h o d f o r t e m p e r a t u r e s b e t w e e n 4.2 a n d 300 K.

1. C o m p o s i t i o n e f f e c t

S p e c i f i c r e s i s t i v i t y Q o f Fel,xBx

0 0.1 0.2 0 3 0.L 0.5 06 0.7 BORON CONCENTRATION

F i g . 1 . T h e room t e m p e r a t u r e r e s i s t i v i t y o f F e l , x B x f i l m s a s a f u n c t i o n o f B c o n - t e n t . ( 0 ) o u r r e s u l t s , ( x ) d a t a a f t e r J.A.Aboaf a n d E , i < l o k h o l m

C Z ~ .

T h e d o t e d l i n e i n d i c a t e s t h e t r a n s i t i o n f r o m

c r y s t a l l i n e ( c ) t o a m o r p h o u s s t a t e (A).

t i m e s o f i t s i n i t i a l v a l u e a n d t h e f i l m s

_- -

f i l m s i n c r e a s e w i t h i n c r e a s i n g c o n c e n t r a -

t i o n o f B / s e e F i g , l / u p t o a b o u t f i v e I -

b e c o m e a m o r p h o u s a t ~ ~ 0 . 1 2 . T h e r e s i s t i - v i t y i n c r e a s e s s l i g h t l y f o r 0 . 1 2 4 ~ 60.40 /1.5 t i m e s / a n d t h e r e i s a r a p i d i n c r e a s e a b o v e x = 0 , 4 0

.

-2 - T e m p e r a t u r e C o e f f i c i e n t . o f R e s i s t i v i t y

0.1 0.2 0.3 0.4 0.5 0:6

T

/TCR/ d e c r e a s e s s u d d e n l y a t t h e t r a n s i - BORON CONCENTRATION t i o n i n t o t h e a m o r p h o u s s t a t e . T h e TCR i s Fig,2, TCR a t room

of

l i n e a r a g a i n s t x a n d c h a n g e s i t s s i g n a t Fel,xBx f i l m s a s a f u n c t i o n o f B c o n t e n t . a b o u t x = 0 . 2 5 , S i m i l a r d e p e n d e n c e o f Q ( x )

I .

-

₂_. T h e d e p e n d e n c e o f t h e r e s i s t i v i t y a n d TCR x w a s o b s e r v e d f o r a m o r p h o u s

o n t e m p e r a t u r e a l l o y s o f Nil,xPx

[37

a n d Pd-Ni l-xPx

F i g . 3 s h o w s t y p i c a l d e p e n d e n c e o f C.47 i n t h e r a n g e o f c o n c e n t r a t i o n

? ( T )

f o r s a m p l e s w i t h d i f f e r e n t c o n c e n -

0.15 \< x 4 0.30 / a l t h o u g h t h e m a g n i t u d e s t r a t i o n o f B. T h e d a t a w e r e f o u n d t o f i t

Article published online by EDP Sciences and available at http://dx.doi.org/10.1051/jphyscol:19808121

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JOURNAL DE PHYSIQUE

t h e f o l l o w i n g e q u a t i o n s f o r x

<

^0.25

,-$$&

⁼a r b i n T

+

cT 2 _-I-

<

^To

= a

+

d ~ T

>

To

f o r x ) 0.25

= a + b l n ~ T < T b

+ & - = a e + ,T > T b

where f ( 3 0 0 ) , a , a - , b , c a n d d a r e l i s t e d i n T a b l e I.

Fig.3. The n o r m a l i z e d r e s i s t i v i t y o f c r y s t a l l i n e /c/ and amorphous /A/

Fel,xBx f i l m s a s a f u n c t i o n o f T.

Low t e m p e r a t u r e dependence o f r e s i s t i v i t y i s shown i n F i g s 4a and 4b, F o r a c r y s t a l - l i n e sample w i t h s m a l l c o n c e n t r a t i o n o f I3 /Fe0.94B0,0S/ One can see weak i n - c r e a s e o f

?

w i t h d e c r e a s i n g temperature.

T h i s t e n d e n c y i s even s t r o n g e r f o r amorphous f i l m s where ?r\.

-

^{I n T.} A monoto- n i c i n c r e a s e o f Tb and b w i t h c o n c e n t r a - t i o n /see T a b l e I and Fig.4/ o f B t a k e s p l a c e .

a

TEMPERATURE [

K l

4 5 7 10 15 20 30 50 70 100

r ' ' ' ' ' *

TEMPERATURE [K 1

Fig.4. The n o r m a l i z e d r e s i s t i v i t y change o f c r y s t a l l i n e / c / and amorphous /A/

Fel,xBx f i l m s v s l o g T; a/ f o r ~ ( 0 . 2 5 and b/ f o r x ?0.25 Tb i n d i c a t e s t h e t e m p e r a t u r e where a d e v i a t i o n f r o m t h e

f w - l n T becomes n o t i c e a b l e ,

The c o e f f i c i e n t c and t e m p e r a t u r e Tb d e c r e a s e w i t h x /Fig.5 and T a b l e I/.

F o r x 7 0.25 /Fig.3/ t h e r e s i s t i v i t y d e c r e a s e s l i n e a r l y v s t e m p e r a t u r e f o r T 7 Tb

.

The d e v i a t i o n f o r T 7~ 200 K c a n b e e x p l a i n e d a s t h e r e s u l t o f s t r e s s

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between s u b s t r a t e and t h e f i l m , T a b l e 11, A c o ~ p a r i s o n o f r e s i s t i v i t y measurements between Fe

1-xox f i l z a n d r i b b o n s

3. C o n c l u s i o n s

We draw f o l l o w i n g c o n c l u s i o n s f r o m e l e c t r i c a l r e s i s t i v i t y z i e c s u r e n e n t s o f amorphous Fel-xBx f i l m s :

*

F i g . 5. The n o r m a l i z e d , r e s i s t i v i t y o f t h e

-

t h e r e i s a t r a n s i t i o n c o n c e n t r a t i o n

X Cofil-

0.18 0.9916 3 1 -6.4 f i l m

0.20 0.968 1 5 -4.5 r i b -

0.17 0.972 1 6

-

crystalline / c / and amorphous /A/

2 r a n g e 0 . 1 2 4 x

4

C.25 where c o n t r i b u - B f i l m s as a f u n c t i o n o f T

.

To i n -

F e l - x x

d i c a t e s t h e t e m p e r a t u r e where d e v i a t i o n t i o n

p -

^C ^T ^~from s p i n wave s c a t t e r i n g f r o m t h e

p

.v

r2

b e h a v i o u r becomes n o t i c e - c h a r a c t e r i s t i c f o r a c r y s t a l l i n e s t a t e ,

a b l e . i s d i r z i n i s h i n g

[77 .

T a b l e I. R e s u l t s o f r e s i s t i v i t y measure-

-

l o w t e m p e r a t u r e r e s i s t i v i t y a n o m a l i e s rnents o f Fel,xBx f i l m s

/ 7 -

b I n T / s t r o n g l y depend nn concen- t r a t i o n o f B. B o t h Tb and b i n c r e a s e w i t h x / T a b l e I/; i t c a n be e x p l a i n e d a f t e r G r e s t and N a g e l [8]

as r e s u l t o f superexchange i n t e r a c t i o n s between n e x t - n e a r s t - n e i g h b o r m a g n e t i c atoms w h i c h a r e s e p a r a t e d b y B o r o n atoms,

-

n e g a t i v e TCR and t e m p e r a t u r e dependence o f Q f o r T > T b f o r f i l m s w i t h x 7 0.25 i s l i k e l y t o be due t o tem- p e r a t u r e dependence o f f o r m f a c t o r

-

d 5 f f e r e n c e s i n between o u r r e s u l t s and g i v e n b y Cochrane

et

a 1

[53

a n d T 6 t h r61

,

e s p e c i a l l y w i t h r e s p e c t t o Tmi

n and

7

(4.2)/ F ( 3 0 G ) /ape T a b l e II/, seem t o i n d i c a t e t h a t s p u t t e r e d

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(28-488 JOURNAL DE PHYSIQUE

f i l m s a r e more amorphous than r i b b o n s . Work was s u p p o r t e d b y D e u t ~ + c 7 r -

s c h u n g s g e m e i n s c h a f t .

R e f e r e n c e s /1/ F . S t o b i e c k i , T . S t o b i e c k i ,

S.Schwarz1, and H.Hof fmann. "Prepa- r a t i o n and structure.,.

",

t h i s Conference.

/2/ J.A.Aboaf, and E.Klokholm, JCM M u n i c h /1979/,

/3/ P.J,Cote, S o l i d S t a t e C o m m u n . , ~ , 1 3 1 1 /1976/.

/4/ B.Y,Bucher. 'J.Non-Cryst,Solids,7, 277 /1972/.

/5/ I?.Vi.Cochrane, F.T.Hedgcoc k, 8. J.Ut!stner, and \J,B.Muir, J.Physique,39.C6-940 /1978/.

/ G / 3,T6th, C o n f e r e n c e S o f t M a g n e t i c M a t e r i a l s 3 . B r a t i s l a v a /1977/.

/7/ D,A,Goodgins. Phys,Rev.,l32, 542

/1963/.

/8/ G.S.Grest and S.R.Nage1, Phys.Rev.

B ,

19,

3 5 7 1 /1979/.

/9/ S.R.Nage1, Phys.Rev.6,

15,

1694

/1977/,