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Ìæ¤É¥C[gÌü«ªÏ»·éàÌðç¹ñ¥ðà ¡ ñÜÀ±©çTé}`tFCNÌådC¥CÌ­»@\Fig. 2(a)Electric dipole moment induced by vector spin chirality.
(b) Cycloidal magnetic order produces macroscopic electric
polarization.20)«ÆÄÑÜ·Bç¹ñ¥«ÉÍ¥C[gÌñ]²ªTCgÌÀÔûüÆêv·éêÆ¼ð·éêª·ªC»ê¼êXN

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Fig. 3(Left) Proles of (4}Qm 1) neutron magnetic reections in
an electrically poled TbMnO3 crystal.24) The spin direction ofincident neutrons is polarized parallel (antiparallel) to thescattering vector, when a spin ipper is turned o (on).
(Right) Relation between the helicity of cycloid magnetismand direction of electric polarization.

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Ch^Ì¥CÌêÅ·B·Èí¿CTCNCh^ç¹ñ¥«Í­Ud«ðUN·éÍ¸Å·BjçÌñÄÆÀs·éæ¤É TbMnO3 Ì­Ud«­»

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½24) BFig. 3 É TbMnO3 É¨¯éXsÎÉ«qÌi4ìpÌÉæéÆvÁÄ¢Ü·B·Èí¿CTbMnO3}Qm 1j¥Cq¯½ËÌvt@Cð¦µÜ·B±Ì

ÅÍ Mn Ì`®¿ª 3 ¿Åæ¤ÉCüË«qÌXsÌü«ðXstbp[ÌMn Ì`®¿ª 2 ¿ÆÈÁÄ¢Ü·BXsO¹ÝìéÌÉÎµCMnWO4 ÅÍúËõ Jan. 2009 Vol.22 No.1  5

Fig. 4

Fig. 5

Wavenumber Qm of magnetic modulation in various distort­
ed perovskite­type manganese oxide compounds RMnO3 as afunction of temperature, which is deduced from the superlat­
tice modulation of charge with Qs2Qm. Arrows indicate
ferroelectric transition temperatures.

Fig. 6(Top) Crystal structure of perovskite­type rare­earth man­ganese oxide compound projected along the c axis. (Bot­tom) GdFeO3­type distortion and orbital order result in fer­romagnetic superexchange interaction between the next­
nearest neighbor Mn ions along the b axis but not along the aaxis.22)Proles of synchrotron x­ray diraction in a DyMnO3 single
crystal along (a) (0 k 2) and (b) (0 k 3) at various temper­
atures below N áeel temperature.

pÌÍ d dqÌª 5 æè½¢©­È¢©ÅÜè
Ü·ªCMn3{ Í 3d dqª 4 ÂÅÅÍ 3d dqÍ 5 ÂÅéÌÉÎµCMn2{èC´ð·ÝìpÌÔóÔÉd 6 óÔªüÁÄ«Ü·B±Ì±Æª A ÌÌá¢Ì´öÅÍÈ¢©Æl¦Ä¢Ü·B
Æ±ëÅC»à»àÈº TbMnO3 ÅTCNCh¥C\¢ªo»·éÌÅµå¤©B±êÉÂ¢ÄÍC®SÈÓÉÁÄ¢éí¯ÅÍèÜ¹ñªC­È­ÆàC¥C

BL_4C Ì 4 ²ñÜvðp¢Äsíê½àÌÅ·Bá·ÅIÈÝìpÌ£ª·üú¥C\¢ðìèoµÄ¢é±s®ÌiqÐ¸Ýª¶Ý·é±Æªí©èÜ·B±ÌæÆÍí©ÁÄ¢Ü·22)B±Ì¤ÌÛÉÍCúËõ X ü¤ÈÀ±ðóyÞ R ÌíÞðÏ¦Èªçs¢Üµ½BFig.

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5 É¥CÏ²g Qm Æ·xÌÖWð¦µÜ·B±ÌUéuXJCg^}K_»¨ RMnO3 nÅ¥CÌo¢ÍCCWOXsÌê³½ÅÅßÚÌXsÔÉ»Æ¯Éi0, 2k{2Qm, ljÌÊuÉ´iq½Ëªo»·­¥«IÈÝìpª­«æñßÚÌXsÔÉ½­¥«

é±Æªí©Á½ÌÅ·B½Æ¦ÎCFig. 4 ÍCDyMnO3

IÈÝìpª­­Æ¢¤Í^iANNNI Í^jÅÌ´\ÉÂ¢Äi0 k 2j¨æÑi0 k 3jÉÁÄúËõ X üñ¢ÌüúÌUé¢Æ»Á­èÅ·23) B·Èí¿CæñÜvt@Cðªèµ½ÊÅ·B±ÌÀ±ÍC±Ì¨

ßÚÌ Mn CIÔÉ½­¥«IÈª¿ª­UdÌÅ

é±ÆðméÈOÉ Photon Factory Ì

6  úËõ Jan. 2009 Vol.22 No.1

é±Æª¤©ª¦Ü·BÎ´ÍCO¹Æ MnO6 Ìñ]ª±Ìæðà ¡ ñÜÀ±©çTé}`tFCNÌådC¥CÌ­»@\¤ÈÝìpð¶Ýo·±Æðà¾µÜµ½22)BFig. 6 É¦·Æ¨èCMnO6 Ìñ]pªå«­ÈéÆCab ÊàÅ 2
ÂÌ_fCIªßt­Îª`¬³êC»ÌÊCMn_O_O_Mn Æ¢¤dqÌòÑÚèªå«­ÈéÅµå¤BO¹®ñðÁ¡·êÎCb ²ûüÌæñßÚ Mn3{ CIÔÉÌÝ½­¥«IÈ´ð·Ýìpª­­±ÆÉÈèÜ
·B±ÌÝìpÍÅßÚ Mn3{ CIÔÌ­¥«IÈ´ð·ÝìpÆ£µÜ·BÀÛCóyÞ R ÌCI
¼aª¬³­ÈÁÄ MnO6 Ìñ]ªå«­ÈéÉÂêÄ
Qm Ìlªå«­ÈèÜ·BÎû» HoMnO3 ÅÍªª««Æ¢¤ 4 TCgüúÌ¥CiQm1/2jªo»µÜ·ªC±êÍæñßÚCIÔÌð·Ýìpª®SÉD¨
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·ÝìpÌ£ÌÊCÀèÈ¥C`Àg Qm ªè

Fig. 7

Uniform (Q0) and spatially modulated (QQm, 2Qm)
displacement of atoms induced by various spiral magnetic
order through the exchange striction and inverse Dzyaloshin­skii­Moriya interaction.29)

Fig. 8Temperature dependence of intensity of an x­ray superlatticereection (0 Qs 3) in TbMnO39).

Fig. 9Superlattice reection in the conical magnetic phase of
CoCr2O4.29) The peak position corresponds to the magnetic
propagation vector obtained by previous neutron diraction
studies.30,31)³êÜ·BQm ª·g·ÅC©ÂCMn3{ CIÌ¥CÙû«ªã¯êÎC¥C\¢ÍêÊIÉç¹ñÆÈéÅµå¤B½¾µC±Ìç¹ñÊªÈº bc ÊÆÈÁÄ¢éÌ©
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24)

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25)
26)
27)

M. N. Baibich, J. M. Broto, A. Fert, F. Nguyen Van Dau, F.
Petro, P. Eitenne, G. Creuzet, A. Friederich and J. Chaze­las: Phys. Rev. Lett. 61, 2472 (1988).
G. Binasch, P. Gr äunberg, F. Saurenbach and W. Zinn: Phys.
Rev. B 39, 4828 (1989).
P. Curie: J. Physique 3, 393 (1894).
I. E. Dzyaloshinskii: Zh. Exp. Teor. Fiz. 37, 881 (1959)[Sov. Phys.­JETP 10, 628 (1960)].
D. N. Astrov: Zh. Exp. Teor. Fiz. 38, 984 (1960); 40, 1035
(1961) [Sov. Phys.­JETP 11, 708 (1960); 13, 729 (1961)].
J. P. Rivera: Ferroelectrics 161, 147 (1993).
G. T. Rado, J. M. Ferrari and W. G. Maisch: Phys. Rev. B
29, 4041 (1984).
M. Fiebig: J. Phys. D: Appl. Phys. 38, R123 (2005).
T. Kimura, T. Goto, H. Shintani, K. Ishizaka, T. Arima andY. Tokura: Nature 426, 55 (2003).
T. Kimura, G. Lawes, T. Goto, Y. Tokura and A. P. Rami­
rez: Phys. Rev. B 71, 224425 (2005).
W. F. Brown, Jr., R. M. Hornreich, and S. Shtrikman: Phys.
Rev. 168 574 (1968).
K. Aizu: J. Phys. Soc. Jpn. 27 387 (1969); Phys. Rev. 2, 754(1970).
H. Schmid: Ferroelectrics 162, 317 (1994).
N. A. Hill: J. Phys. Chem. B 104, 6694 (2000).
½¾µCY. Noda et al.: J. Phys.: Cond. Matt. 20 434206(2008) É éæ¤ÉCRMn2O5 ÉÖ·éßjêYÌêAÌ¤ð»ÝÌ_Å©êÎC½­¥«UN­¥«Í¾ç
©Å éD
T. Goto, T. Kimura, G. Lawes, A. P. Ramirez and Y.
Tokura: Phys. Rev. Lett. 92, 257201 (2004).
N. Aliouane, O. Prokhnenko, R. Feyerherm, M. Mostovoy,
J. Strempfer, K. Habicht, K. C. Rule, E. Dudzik, A. U. B.
Wolter, A. Maljuk and D. N. Argyriou: J. Phys.: Cond. Matt.
20, 434215 (2008).
S. Quezel, F. Tcheou, J. Rossat­Mignod, G. Quezel and E.
Roudaut: Physica B & C 86_88, 916 (1977).
M. Kenzelmann, A. B. Harris, S. Jonas, C. Broholm, J.
Schefer, S. B. Kim, C. L. Zhang, S.­W. Cheong, O. P. Vajk
and J. W. Lynn: Phys. Rev. Lett. 95, 087206 (2005).
H. Katsura, N. Nagaosa and Balatzky: Phys. Rev. Lett. 95,
057205 (2005).
I. A. Sergienko and E. Dagotto: Phys. Rev. B 73, 094434(2006).
T. Kimura, S. Ishihara, H. Shintani, T. Arima, K. T. Taka­hashi, K. Ishizaka and Y. Tokura: Phys. Rev. B 68, 060403R(2003).
P. Bak and J. von Boehm: Phys. Rev. B 21, 5297 (1980).
Y. Yamasaki, H. Sagayama, T. Goto, M. Matsuura, K. Hiro­ta, T. Arima and Y. Tokura: Phys. Rev. Lett. 98, 147204(2007).
M. Blume: Phys. Rev. 130, 1670 (1963).
K. Siratori, J. Akimitsu, E. Kita and M. Nishi:, J. Phys. Soc.
Jpn. 48, 1111 (1979).
H. Sagayama, K. Taniguchi, N. Abe, T. Arima, M. Soda, M.
Matsuura and K. Hirota: Phys. Rev. B 77, 220407(R)úËõ Jan. 2009 Vol.22 No.1  9

28)
29)

30)
31)
32)

33)

34)
35)
36)

37)
38)

(2008).
H. Ohsumi and K. Tajima: J. Phys. Soc. Jpn. 67, 1883
(1998).
T. Arima, Y. Yamasaki, T. Goto, S. Iguchi, K. Ohgushi, S.
Miyasaka and Y. Tokura: J. Phys. Soc. Jpn. 76, 023602(2007).
N. Menyuk, K. Dwight and A. Wold: J. Phys. 25, 528(1964).
K. Tomiyasu, J. Fukunaga and H. Suzuki: Phys. Rev. B 70,
214434 (2004).
T. Arima, T. Goto, Y. Yamasaki, S. Miyasaka, K. Ishii, M.
Tsubota, T. Inami, Y. Murakami and Y. Tokura: Phys. Rev.
B 72, 100102(R) (2005).
A. M. Kadomtseva, Yu. F. Popov, G. P. Vorob'ev, K. I.
Kamilov, A. P. Pyatakov, V. Yu. Ivanov, A. A. Mukhin and
A. M. Balbashov: JETP Lett. 81, 19 (2005).
K. Noda, S. Nakamura, J. Nagayama and H. Kuwahara: J.
Appl. Phys. 97, 10C103 (2005).
T. Goto, Y. Yamasaki, H. Watanabe, T. Kimura and Y.
Tokura: Phys. Rev. B 72, 220403 (2005).
Y. Yamasaki, H. Sagayama, N. Abe, T. Arima, K. Sasai, M.
Matsuura, K. Hirota, D. Okuyama, Y. Noda and Y. Tokura:Phys. Rev. Lett. 101, 097204 (2008).
T. Kimura, J. C. Lashley and A. P. Ramirez: Phys. Rev. B
73, 220401(R) (2006).
K. Taniguchi, N. Abe, T. Takenobu, Y. Iwasa and T. Arima:

Phys. Rev. Lett. 97, 097203 (2006).
K. Taniguchi, N. Abe, H. Sagayama, S. Ohtani, T.
Takenobu, Y. Iwasa and T. Arima: Phys. Rev. B 77, 064408(2008).
40) H. Kimura, Y. Kamada, Y. Noda, K. Kaneko, N. Metoki andK. Kohn: J. Phys. Soc. Jpn. 75, 113701 (2006).
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E­mail: arimatagen.tohoku.ac.jpêåFÞ¿Èw
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1988åwåw@Hwn¤È¨HwêUCmC¹C
1994miwjC®ïÐªq¤Cåww
èCåwHwn¤ÈèC}gåw¨¿Hwn³öðoÄ C2004N 7 æè kåw½ ³¨¿ Èw¤ ³öC»ÝÉéB2007N 4 æè»w¤±B

Diraction Studies on the Origin of Giant
Magneto­electric Eects in Multiferroics
Taka­hisa ARIMA

Institute of Multidisciplinary Research for Advanced Materials, Tohoku University,
2_1_1 Katahira, Aoba, Sendai 980_8577
RIKEN SPring­8 Center, 1_1_1 Koto, Sayo, Hyogo 679_5148

Abstract Magnetic ferroelectrics termed multiferroics often exhibit a giant magneto­electric response suchas an appearance, disappearance, and rotation of ferroelectric polarization by the application of a magnetic
eld. In most multiferroics, long­wavelength spiral magnetic order arises from the competition among somemagnetic exchange interactions. Spin­polarized neutron diraction studies reveal that the ferroelectric polari­zation direction corresponds to the helicity of spiral magnetism. A change in magnetic order with the applica­tion of a magnetic eld has been investigated for various multiferroics by means of synchrotron x­ray dirac­tion, because it can provide us some information about the periodicity and type of magnetic order.

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