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Effects of field annealing on the magnetic characteristics and magnetic losses of amorphous ribbons Fe78Si10B12
Journal of Magnetism and Magnetic Materials 31-34 (1983) 1563-1564
1563
EFFECTS OF FIELD ANNEALING ON THE MAGNETIC CHARACTERISTICS MAGNETIC LOSSES OF AMORPHOUS RIBBONS Fe7sSil0Biz Y.C. K U O , L.S. Z H A N G
AND
and R.W. GAO
Phystcs Department, Shandong Umverslty. Jman, Chma T h e effects of m a g n e t i c a n n e a l i n g o n the m a g n e t i c c h a r a c t e r i s t i c s a n d m a g n e t i c losses of a m o r p h o u s r i b b o n s Fe78SI J0 BI2 were stud~ed. T h e a n n e a l i n g t e m p e r a t u r e w a s c h o s e n at 4 0 0 ° C , b e i n g l o w e r t h a n the C u r i e t e m p e r a t u r e 4 4 0 ° C A m a g n e t i c field of 30 O e w a s a p p l i e d d u r i n g the h e a t t r e a t m e n t , in a d i r e c t i o n at a n a n g l e 0 to the l e n g t h of the r i b b o n , w~th 0 = 0% 45 °, 60 °, 90 ° T h e m a g n e t i c c h a r a c t e r i s t i c s m ac fields were m e a s u r e d w~th the f r e q u e n o e s f r o m 50 H z to 10 k H z T h e total losses W w e r e m e a s u r e d a n d resolved i n t o the hysteresis loss W h, the classical e d d y c u r r e n t loss We, a n d the a n o m a l o u s e d d y c u r r e n t loss We~ In general, at a given f r e q u e n c y a n d a given m a x i m u m r e d u c t i o n , We. d e c r e a s e s a n d W h i n c r e a s e s with the d i r e c t i o n 0 So the o p t i m u m a n n e a h n g c o n d m o n s for lowest total loss are d i f f e r e n t for d i f f e r e n t f r e q u e n c y a n d m a x i m u m m d u c t m n 8(kG)
I. Introduction The effects of field a n n e a l m g on the magnetic charactenstlcs a n d magnetic losses of a m o r p h o u s r i b b o n s of high induction h a d been studied by several authors [1,2]. For instance, F u j i m o n [3] made a systematic study of oblique field a n n e a h n g on the core loss in Fe81(B, C, S119 a m o r p h o u s ribbons a n d gave an interpretation of the physical m e c h a m s m involved. We have also studied the effects of field a n n e a h n g on the magnetic characteristic a n d magnetic loss of a m o r p h o u s ribbons FevsSll0B~2 T h e saturation induction 4~'M~ was measured to be 15400 G. The a n n e a h n g temperature was chosen at 400°C. A magnetic field of 30 Oe was applied during the annealing m a direction at an angle 0 to the length of the ribbon, with 0 = 0 °, 45 °, 60 °, 90 °. The magnetic characteristics in dc a n d m ac fields with frequencies from 50 Hz to 10 kHz were measured. The m a g n e n c losses at different frequencies a n d different m a x i m u m reductions were also evaluated by the area of the B - H loops traced by a recording fluxmeter. The wave form of B flux was very close to a sine wave
J
12
10
8 1 0=0
0304-8853/83/0000-0000/$03.00
© 1983 N o r t h - H o l l a n d
°
2 0 = 45 ° 3 0 = 60 ° 4 0 = 90 °
6
4
2
2. Results and discussion Fig 1 shows the magnetic charactertstlcs of the sample in dc field after o b h q u e field annealing. It is seen that annealing in longitudinal field ( 0 = 0 °) is very efficient m reducing the coerclvlty H c and improving the residual induction (normalized) B r / B m. This may be due to the unlaxlcal amsotropy induced by the longitudinal field, thus increasing the n u m b e r of fine parallelstriped domains, a n d easing the m a g n e t l z a h o n process, so that the magnetization curve goes up very rapidly to saturation. After 0 >~ 50 °, H c begins to increase and B r / B m begins to decrease This IS clearly shown in fig. 2. The total loss W was supported to consist of three parts the hysteresis loss W h, the classical eddy current loss We calculated by the formula for infinite plane, and the a n a m a l o u s eddy current loss We, obtained by subtractlng W h a n d We from W Fig. 3 shows the variation of the total loss W w~th the direction 0 of annealing
2
14
0
I
0.4
I
O8
I
1.2
I
1.6
2.0 H(Oe) Fag 1 T h e d c m a g n e t i z a t i o n c u r v e o f Fe78SIIoB12 a f t e r h e a t t r e a t m e n t at Ta = 4 0 0 ° C a n d in m a g n e t i c field H a = 30 O e in different &rectlons 0
field at a given m a x i m u m induction B m 10 k G This figure shows clearly that the o p t i m u m direction of annealing field is different for different frequency of ac field Figs. 4 a n d 5 give the variation of total loss W and also of the three constituent parts of W wtth the direction of annealing field 0. In general, at a given frequency f a n d m a x i m u m induction B m, W~a decreases a n d W h increases with the annealing field direction 0, whde the We remains practically constant. Thus the o p t i m u m annealing conditions for lowest total loss are different for different f and different Bm.
Y C Kuo et a l / Amorphou~ ribbons Fe,~StzoBj: andfwld anneahng
1564
Hc(Oe) 014
BrlB n
10
W(x lO0erg/cm3) 5 f =400Hz Bm = lOkG
08
012 4-
06
010
04
008
Wh 2
02
006 1
b
1
I
20
40
l
a
60 80 0 (degree) Fig 2 The vanatmn of H~ and B r / B m of Fe78SlmB12 with different annealing field directions (T~ = 400°C, H a = 30 Oe)
L, 0
I 20
I [ 40 60 0 (degree)
I 80
Fig, 4 The vdnatlon of total loss W and the constituent parts in FeTsS110B12 with different anneahng field directions ( f = 400 Hz, B m = 1 0 k G )
3. Conclusions T h e o p t i m u m field a n n e a l i n g m the direction 0 for lowest total loss v a n e s w i t h the f r e q u e n c y f, the max~m u m m a g n e t i c r e d u c t i o n a n d the a n n e a h n g t e m p e r a ture F o r the a m o r p h o u s r i b b o n Fe78SlmB12 field annealed at T~ = 400°C, w h e n f = 50 H z a n d B m = 10 kG, 0 = 45 ° is the o p t i m u m direction, w h e n f = 400 H z - 2 kHz, 0 = 60 ° is the o p t i m u m direction, w h e n f = 3 - 1 0 W(xlO0 erg/cm3) Bm = 10kG 16
kHz, 0 = 90 ° is the o p U m u m direction T h e p o w e r loss at B m = 1 25 T a n d f = 50 H z is 0 22 W / k g , which rises to 17 W / k g a n d 5 4 2 W / k g at f = 4 0 0 Hz a n d f = 1 kHz, r e s p e c u v e l y T h e loss is a b o u t one-fifth to one-seve n t h of the loss m C h m e s e S t a n d a r d Sdlcon Steel D340
Reference~
[1] R Hasegawa and R C O'Handley, Appl Phys Lett 29 (1976) 219 [2] F E Luborsky and J L Walter, IEEE Trans MAG-I6 (1980) 572 [3] H Fujlmon and H Yoshimoto, J Appl Phys 52 (1981) 1893 W(x 100erg/cm3) 20 /-
f = 10kHz
/
12
1
6
~
Bin= lOkG
W 12
8 ""'--~'~.~
= 400Hz
-
f = 50Hz "
0
I
I
20
40
~
4
~
I
I
60 80 0 (degree) Fig 3 The curve of total magnetic loss W in Fe78S, t0Bi2 versus anneahng field dlrecton 0 for different frequencies (Td = 400°C, H, = 30 Oe)
0
I
20
I
40
1
I
60 80 0 (degree) Fig 5 The vanaUon of total loss W and the constituent parts in FevsSll0Bi2 with different annealing field dlrecUons ( f - 10 kHz, Bm = 10 kG)
1563
EFFECTS OF FIELD ANNEALING ON THE MAGNETIC CHARACTERISTICS MAGNETIC LOSSES OF AMORPHOUS RIBBONS Fe7sSil0Biz Y.C. K U O , L.S. Z H A N G
AND
and R.W. GAO
Phystcs Department, Shandong Umverslty. Jman, Chma T h e effects of m a g n e t i c a n n e a l i n g o n the m a g n e t i c c h a r a c t e r i s t i c s a n d m a g n e t i c losses of a m o r p h o u s r i b b o n s Fe78SI J0 BI2 were stud~ed. T h e a n n e a l i n g t e m p e r a t u r e w a s c h o s e n at 4 0 0 ° C , b e i n g l o w e r t h a n the C u r i e t e m p e r a t u r e 4 4 0 ° C A m a g n e t i c field of 30 O e w a s a p p l i e d d u r i n g the h e a t t r e a t m e n t , in a d i r e c t i o n at a n a n g l e 0 to the l e n g t h of the r i b b o n , w~th 0 = 0% 45 °, 60 °, 90 ° T h e m a g n e t i c c h a r a c t e r i s t i c s m ac fields were m e a s u r e d w~th the f r e q u e n o e s f r o m 50 H z to 10 k H z T h e total losses W w e r e m e a s u r e d a n d resolved i n t o the hysteresis loss W h, the classical e d d y c u r r e n t loss We, a n d the a n o m a l o u s e d d y c u r r e n t loss We~ In general, at a given f r e q u e n c y a n d a given m a x i m u m r e d u c t i o n , We. d e c r e a s e s a n d W h i n c r e a s e s with the d i r e c t i o n 0 So the o p t i m u m a n n e a h n g c o n d m o n s for lowest total loss are d i f f e r e n t for d i f f e r e n t f r e q u e n c y a n d m a x i m u m m d u c t m n 8(kG)
I. Introduction The effects of field a n n e a l m g on the magnetic charactenstlcs a n d magnetic losses of a m o r p h o u s r i b b o n s of high induction h a d been studied by several authors [1,2]. For instance, F u j i m o n [3] made a systematic study of oblique field a n n e a h n g on the core loss in Fe81(B, C, S119 a m o r p h o u s ribbons a n d gave an interpretation of the physical m e c h a m s m involved. We have also studied the effects of field a n n e a h n g on the magnetic characteristic a n d magnetic loss of a m o r p h o u s ribbons FevsSll0B~2 T h e saturation induction 4~'M~ was measured to be 15400 G. The a n n e a h n g temperature was chosen at 400°C. A magnetic field of 30 Oe was applied during the annealing m a direction at an angle 0 to the length of the ribbon, with 0 = 0 °, 45 °, 60 °, 90 °. The magnetic characteristics in dc a n d m ac fields with frequencies from 50 Hz to 10 kHz were measured. The m a g n e n c losses at different frequencies a n d different m a x i m u m reductions were also evaluated by the area of the B - H loops traced by a recording fluxmeter. The wave form of B flux was very close to a sine wave
J
12
10
8 1 0=0
0304-8853/83/0000-0000/$03.00
© 1983 N o r t h - H o l l a n d
°
2 0 = 45 ° 3 0 = 60 ° 4 0 = 90 °
6
4
2
2. Results and discussion Fig 1 shows the magnetic charactertstlcs of the sample in dc field after o b h q u e field annealing. It is seen that annealing in longitudinal field ( 0 = 0 °) is very efficient m reducing the coerclvlty H c and improving the residual induction (normalized) B r / B m. This may be due to the unlaxlcal amsotropy induced by the longitudinal field, thus increasing the n u m b e r of fine parallelstriped domains, a n d easing the m a g n e t l z a h o n process, so that the magnetization curve goes up very rapidly to saturation. After 0 >~ 50 °, H c begins to increase and B r / B m begins to decrease This IS clearly shown in fig. 2. The total loss W was supported to consist of three parts the hysteresis loss W h, the classical eddy current loss We calculated by the formula for infinite plane, and the a n a m a l o u s eddy current loss We, obtained by subtractlng W h a n d We from W Fig. 3 shows the variation of the total loss W w~th the direction 0 of annealing
2
14
0
I
0.4
I
O8
I
1.2
I
1.6
2.0 H(Oe) Fag 1 T h e d c m a g n e t i z a t i o n c u r v e o f Fe78SIIoB12 a f t e r h e a t t r e a t m e n t at Ta = 4 0 0 ° C a n d in m a g n e t i c field H a = 30 O e in different &rectlons 0
field at a given m a x i m u m induction B m 10 k G This figure shows clearly that the o p t i m u m direction of annealing field is different for different frequency of ac field Figs. 4 a n d 5 give the variation of total loss W and also of the three constituent parts of W wtth the direction of annealing field 0. In general, at a given frequency f a n d m a x i m u m induction B m, W~a decreases a n d W h increases with the annealing field direction 0, whde the We remains practically constant. Thus the o p t i m u m annealing conditions for lowest total loss are different for different f and different Bm.
Y C Kuo et a l / Amorphou~ ribbons Fe,~StzoBj: andfwld anneahng
1564
Hc(Oe) 014
BrlB n
10
W(x lO0erg/cm3) 5 f =400Hz Bm = lOkG
08
012 4-
06
010
04
008
Wh 2
02
006 1
b
1
I
20
40
l
a
60 80 0 (degree) Fig 2 The vanatmn of H~ and B r / B m of Fe78SlmB12 with different annealing field directions (T~ = 400°C, H a = 30 Oe)
L, 0
I 20
I [ 40 60 0 (degree)
I 80
Fig, 4 The vdnatlon of total loss W and the constituent parts in FeTsS110B12 with different anneahng field directions ( f = 400 Hz, B m = 1 0 k G )
3. Conclusions T h e o p t i m u m field a n n e a l i n g m the direction 0 for lowest total loss v a n e s w i t h the f r e q u e n c y f, the max~m u m m a g n e t i c r e d u c t i o n a n d the a n n e a h n g t e m p e r a ture F o r the a m o r p h o u s r i b b o n Fe78SlmB12 field annealed at T~ = 400°C, w h e n f = 50 H z a n d B m = 10 kG, 0 = 45 ° is the o p t i m u m direction, w h e n f = 400 H z - 2 kHz, 0 = 60 ° is the o p t i m u m direction, w h e n f = 3 - 1 0 W(xlO0 erg/cm3) Bm = 10kG 16
kHz, 0 = 90 ° is the o p U m u m direction T h e p o w e r loss at B m = 1 25 T a n d f = 50 H z is 0 22 W / k g , which rises to 17 W / k g a n d 5 4 2 W / k g at f = 4 0 0 Hz a n d f = 1 kHz, r e s p e c u v e l y T h e loss is a b o u t one-fifth to one-seve n t h of the loss m C h m e s e S t a n d a r d Sdlcon Steel D340
Reference~
[1] R Hasegawa and R C O'Handley, Appl Phys Lett 29 (1976) 219 [2] F E Luborsky and J L Walter, IEEE Trans MAG-I6 (1980) 572 [3] H Fujlmon and H Yoshimoto, J Appl Phys 52 (1981) 1893 W(x 100erg/cm3) 20 /-
f = 10kHz
/
12
1
6
~
Bin= lOkG
W 12
8 ""'--~'~.~
= 400Hz
-
f = 50Hz "
0
I
I
20
40
~
4
~
I
I
60 80 0 (degree) Fig 3 The curve of total magnetic loss W in Fe78S, t0Bi2 versus anneahng field dlrecton 0 for different frequencies (Td = 400°C, H, = 30 Oe)
0
I
20
I
40
1
I
60 80 0 (degree) Fig 5 The vanaUon of total loss W and the constituent parts in FevsSll0Bi2 with different annealing field dlrecUons ( f - 10 kHz, Bm = 10 kG)