Документ взят из кэша поисковой машины. Адрес оригинального документа : http://danp.sinp.msu.ru/MagNanoS/L10.pdf Дата изменения: Mon Nov 14 18:05:30 2005 Дата индексирования: Mon Oct 1 20:44:08 2012 Кодировка:

X. . . . . . . . . . . -. . , ,

.10.1. .
. . 10.1. . .10.2. : (a) || () [100]; (b) H || [110]. , (). (D), H=-Hc, . VI , . . . 10.2 || [100] (.. ) (a) H || [110] (b). , . . 10.3. . 10.3 [111] 3 Fe . . , S s, . 10.4. 1800- W = 2IsSsH = pSs. (10.1) p = 2MsH (10.2a) , Is p = 2IsHcos . (10.2)

Fe.


900- , 1 2 Is : p = 2IsH(cos 1-cos 2). (10.2) [1]. , [2], . 10.5. Ms, (10.2) «» . 10.5. , . r , .10.4. /r = p = 2IsHcos. (10.3) M = (4/3) Is (cos)Ss, (10.4) S ­ . s s = l2/(8r), (10.5) I = (Sl2Is2/3) cos2 . (10.6) , =1/3, 1800- a,180 = Sl2Is2/(9) (10.7) () , l = 2lIs2/(9) (10.8) Is = 2.15 (/2), = 1.6 10-3, l = 10-4 , , 2x(2.15)2 x10-4/[9x1.6x10-3x4x10-7] = 51 000 10 000. .. . , , . , [3], . , . 10.6. (10.2), .10.6. , , . , (!) w/s = p = 2IsHcos . (10.9) , s1 . 10.6, , s2, (10.9) . , . , , H0 = [1/(2Iscos )]( w/s). (10.10) . , , . . , 0 , , . 10.7. : E = -Kucos2(0 - ) ­ IsH cos . (10.11) (10.11) , / = 0 . . 10.8 .10.7. , . I/Is = cos (10.12)


( h = IsH/Ku) 0. , 0 = 900 : cos = IsH/(2Ku). (10.13) I = Is2H/(2Ku), (10.14) . , .. , H = 2Ku/Is. 0 , , .. , , . 10.8. . 10.8. , H = 2Ku/Is , , . , 900! . (Wohlfarth..), , . 10.9, . , ­ 0 . x. E = -Kucos2(-0) + IsH cos . (10.15) / = Kusin2(-0) - IsH sin = 0. (10.16) , 2/2>0 , 2/2<0. . 10.9. , 0 ­. (18.28) , .. 2/2 = 0. (10.16) 2/2 = Kucos2(-0) - IsH0 cos = 0. (10.17) (10.16) (10.17) sin 2(-0) = h sin cos 2(-0) = h/2 cos , h = H0Is/Ku. (10.18) : sin = [(4-h2)/(3h2)] cos = ±2[(h2-1)/(3h2)]. (10.19) sin 20 = [(4-h2)/3]3/2 /h2. (10.20) h(0) . 10.10. , , 0 = 450. , H0 = Ku/Is. (10.21) 0 = 00 0 = 900, H0 = 2Ku/Is. (10.22) ( ). , , H0 = 2K1/Is, (K1>0) (10.23) .10.10. H0 = -4K1/(3Is) (K1<0) (10.23) 0 0. Ms=1-2 K1=104-105 /3, H0 = 4 5 10 -10 / ( = 102-103 ). ! .. , !


. . , .. , ­ . = 0exp(it), . = / = 0exp(it-i)/0exp(it) = (0/0)exp(-i)= = (0/0)cos ­i(0/0)sin. (10.24) = ­ i'', ' = (0/0)cos, ''= (0/0)sin. (10.25) ' B, , , .. '- . '' , /2. . ''/'= tan . (10.26) tan . /tan . . , . , , , , . (eddy current loss). . , . r , .10.11, Esds = -(dBn/dt) dS. (10.27) M, 2rE(r) = -r2(dI/dt) E(r) = -(r/2)(dI/dt). (10.28) : i(r) = -(r/2) dI/dt, (10.29) ­ . : P = (1/r02) 0r02E(r)i(r)rdr = (1/2r02)(dI/dt)20r0r3 dr = = r02/(8)(dI/dt)2. (10.30) .. , .. , . .. . , P ~ r02. , . . . 10.11. , , . .. , , . . , Ni- (~100 ), , , Fe2+, . , . , , . dI/dt , , , . , r , . , . , . - s = (2/)1/2 (10.31)


­ ­ . s - . = 1 10-7 (10 ), <> = 500 50 s = [2110-7/(250500410-7)] 1.010-3 () = 1 . 1 s210-4=0.2. , , . (magnetic after-effect). , , . - . (aging). , . , 1 2, I1 Ii , . 10.12. In(t) , In(t) = In0(1-exp(-t/)). (10.32) . 10.12. I = aH{1+(1-exp(-t/))}, (10.33) . = In0/ Ii. d(I-aH)/dt = -{ I-aH(1+ )}/ (10.34) (10.33). H = H0exp(it), (10.35) I = I0exp (it ­i). (10.36) (10.35) (10.36) (10.34) tan = /(1++22), (10.37), I0 = aH/( cos ­ sin ). (10.38) , , tan ­ . .10.13. . . 10.13, tan tan . . tan 200 4 [5]. , , = (1+)1/2/. (10.39) [5]. , , , , , .10.14. , , , . 10.14. [6]. , . . . , ( -) [6]. , , . 10.15. , . . <> <> . ,


= /[f(<><>)-1/2]. (10.40) <> ~ 5 104 <> ~ 103, Mn-Zn, [6], f=1.5 2.6 , . , , . '(f) , . . , . . 10.16 Ni-Zn [7]. , . [8] . 10.15. . , =0, [7]. = , (10.41) , (9.8) = gB = ge0/(2m) = 1.105 105g (/()), g g=2.0232 ­ . (10.41), , ' ''. 1 = -5 102 /3, s = 0.3 , Ni-Zr, (10.23) = (45102)/(3310-1) 2.2103(/) (27 ). g =2, (10.41) = (1.105105)22.2103) 5108, f = /(2) 8 107 (80 ). , . .
B

. 1>0, (10.23), = 21/Is. = 21/ Is. (10.42) , 1 : <> = Is2/(3K10). (10.43) , <> = 2 Is/(30). (10.44) 1<0. Is = 0.3 = 4 10-7<>, f<> 5.6 109 = 5.6 . (10.45) . 10.16 ' . 10.16. 0.5 . [8]. (10.45) . . (10.45) . , . -. [9]. , .10.17. - (-) : dI/dt = (Iвeff) - (/I)(Iв(Iвeff)),

(10.46)


eff ­ , - , - . , .. = 0, , . 10.17. , , . 10.17. - . 10.17. (), () () . . , . , , , . . 10.18 - 9 , - () () - 10 100 H0.

. 10.18. . () () [10]. f H . "" , . .

1. 2. 3. 4. 5. 6. 7. 8. 9. 10.

L. NИel, Annal Univ. Grenoble, 22 (1946), 299 M. Kersten, Z. F. Angew. Phys. 7 (1956) 313; 8 (1956) 382, 496 . Kondorsky, Phys. Z. Sowjet., 11 (1937) 597 Y. Tomo, J. Phys. Soc. Japan 7 (1952) 180 J.L. Snoek, Physica, 5 (1938) 663 F.G. Brockman, P.H. Dowling and W.G. Steneck, Phys. Rev, 77 (1950) 85 E.W. Gorter, Proc. IRE, 43 (1955) 245 J.L. Snoek, Physica, 14 (1948) 207 L. Landau and E.Lifshitz, Phys. Z. Sowjetunion, 8, (1935) p.153 .., . , 5 (1997)


: 1. Fe, , [111]. 2. . 3. ? ? 4. ? 5. , 900 ? 6. . , ? 7. . 8. ? 9. ? ? 10. ? 11. ? 12. -? : 1. .. . - , 1985. 336 . 2. .. . ., 1971 3. . . - . , -, 1956, 784 .