？ SINGH S K. FeRAMs to provide very low power, high Speeds for new mobile electronic products [C]// Fujitsu Microelectronics America, Inc., Sunnyvale, CA, Press Release, 2006, http://www.fujitsu.com/ca/en/ news/pr/fma_20060802.html.
[2]
？ YANG H, JAIN M, SUVOROVA N A, et al. Temperature-dependent leakage mechanisms of Pt/BiFeO3/SrRuO3 thin film capacitors [J]. Appl Phys Lett, 2007, 91: 072911.
[3]
？ QI X, DHO J, TOMOV R, et al. Greatly reduced leakage current and conduction mechanism in aliovalent-ion-doped BiFeO3 [J]. Appl Phys Lett, 2005, 86: 062903.
[4]
？ PALAI R, KATIYAR R S, SCHMID H, et al. β phase and γ-β metal-insulator transition in multiferroic BiFeO3[J]. Phys Rev B, 2008, 77: 014110.
[5]
？ YANG H, LUO H M, WANG H, et al. Rectifying current-voltage characteristics of BiFeO3/Nb-doped SrTiO3 heterojunction [J]. Appl Phys Lett, 2008, 92: 102113.
[6]
？ JIANG A Q, WANG C, JIN K J, et al. A resistive memory in semiconducting BiFeO3 thin-film capacitors [J]. Adv Mater, 2011, 23: 1277.
[7]
？ YANG C H, SEIDEL J, KIM S Y, et al. Electric modulation of conduction in multiferroic Ca-doped BiFeO3 films [J]. Nat Mater, 2009, 8: 458-493; SEIDEL J, LUO W, SURESHA S J, et al, Prominent electrochromism through vacancy-order melting in a complex oxide [J]. Nat Comm, 2012, 3: 799–803.
[8]
？ KISELEV S V, ZEROV R P, ZHDANOV G S. Detection of magnetic order in ferroelectric BiFeO3 by neutron diffraction [J]. Sov. Phys. Dokl. 1963, 7: 742–735.
[9]
？ YUDIN V M. Magnetic Properties of BiFeO3 [J]. Sov Phys Solid St, 1966, 8: 217–269.
[10]
？ FISHER P, POLOMSKA M, SOSNOWSKA I, et al. Temperature dependence of the crystal and magnetic structures of BiFeO3 [J]. J Phys C: Solid St Phys, 1980, 13: 1931–1933.
[11]
？ EDERER C, SPALDIN N A. Recent progress in first-principles studies of magnetoelectric multiferroics [J]. Current Opinion Solid State Mater Sci, 2005, 9: 128–139.
[12]
？ EDERER C, SPALDIN N A. Weak ferromagnetism and magnetoelectric coupling in bismuth ferrite [J]. Phys Rev B, 2005, 71: 060401.
[13]
？ ALBRECHT D, LISENKOV S, REN W, et al. Ferromagnetism in multiferroic BiFeO3 films: A first-principles-based study [J]. Phys Rev B, 2010, 81: 140401.
[14]
？ LEBEUGLE D, COLSON D, FORGET A, et al. Electric-field-induced spin flop in BiFeO3 single crystals at room temperature [J]. Phys Rev Lett, 2008, 100: 227602.
[15]
？ HOLCOMB M B, MARTIN L W, SCHOLL A, et al. Probing the evolution of antiferromagnetism in multiferroics [J]. Phys Rev B, 2010, 81: 134406; ZHAO T, SCHOLL A, ZAVALICHE F, Electrical control of antiferromagnetic domains in multiferroic BiFeO3 films at room temperature [J]. Nat Mater, 2006, 5: 823–829.
[16]
？ WOJDEL J C, INIGUEZ J. Ab Initio indications for giant magnetoelectric effects driven by structural softness [J]. Phys Rev Lett, 2010, 105: 037208.
[17]
？ DIEGUEZ O, GONZALEZ-VAZQUEZ O E, WOJDEL J C, et al. First- principles predictions of low-energy phases of multiferroic BiFeO3 [J]. Phys Rev B, 2011, 83: 094105.
[18]
？ ESCORIHUELA-SAYALEEO C, DIEGUEZ O, INIGUEZ J, et al. Strain engineering magnetic frustration in perovskite oxide thin films [J]. Phys Rev Lett, 2012, 109: 247202.
[19]
？ INFANTE I C, JURASZEK J, FUSIL S et al. Multiferroic phase transition near room temperature in BiFeO3 Films [J]. Phys Rev Lett, 2012, 107: 237601.
[20]
？ MACDOUGALL G J, Christen H M, Siemons W, et al. Antiferromagnetic transitions in tetragonal-like BiFeO3 [J]. Phys Rev B, 2012, 85: 100406.
[21]
？ KO K, JUNG M H, HE Q, et al. Concurrent transition of ferroelectric and magnetic ordering near room temperature [J]. Nat Commun, 2011, 2, 567–571.
[22]
？ Liu H J, LIANG C W, LIANG W I, et al. Strain-driven phase boundaries in BiFeO3 thin films studied by atomic force microscopy and X-ray diffraction [J]. Phys Rev B, 2012, 85: 014104.
[23]
？ He Q, Chu Y H, Heron J T, et al, Electrically controllable spontaneous magnetism in nanoscale mixed phase multiferroics [J]. Nat Commun, 2011, 2: 225.
[24]
？
[25]
？ BROWN W F, HORNREICH R M, SHTRIKMAN S. Upper bound on the magnetoelectric susceptibility [J]. Phys Rev, 1968, 168: 574–577.
[26]
？ CURIE P. Sur la symétrie dans les phénomenes physiques, symétrie d'un champ électrique et d'un champ magnétique [J]. J Physique, 1894, 3: 393–415.
[27]
？ SMOLENSKII G A, CHUPIS I E. Ferroelectromagnets [J]. Usp Fiz Nauk, 1982, 137: 415–448.
[28]
？ SMOLENSKII G A, ISUPOV V A, AGRANOVSKAYA A I, et al. New ferroelectrics of complex composition [J]. Sov Phys Solid State, 1959, 1: 907–908.
[29]
？ DRABKIN G M, ZABIDAROV E I, KOVALEV A V. Spontaneous magnetization and domain formation in ferromagnets near the Curie point [J]. Zh Eksp Teor Fiz, 1975, 69: 1804–1816.
[30]
？ VENEVTSEV Y N, GAGULIN V V, ZHITOMIRSKY I D. Material science aspects of seignette-magnetism problem [J]. Ferroelectrics, 1987, 73: 221–248.
[31]
？ FOX D L, SCOTT J F. Ferroelectrically induced ferromagnetism [J]. J Phys CM, 1977, 10: L329–L331.
[32]
？ FIEBIG M, FROHLICH D, KOHN K, et al. Determination of the magnetic symmetry of hexagonal manganites by second harmonic generation [J]. Phys Rev Lett, 2000, 84: 5620–5623.
[33]
？ Hill N A, Rabe K M. First-principles investigation of ferromagnetism and ferroelectricity in bismuth manganite [J]. Phys Rev B, 1999, 59: 8759–8769.
[34]
？ GUO H Y, WILSON I H, XU J B, et al. Aging effect on the ferroelectric property of YMnO3 thin film [J]. Ferroelectrics, 2001, 259: 181–185.
[35]
？ SMOLENSKY G A, ISUPOV V A, AGRONOVSKAYA A I. A new group of ferroelectrics-(with layered structure)[J]. Sov Phys Solid State, 1959, 1: 149–150.
[36]
？ WANG J, NEATON J B, ZHENG H, et al. Epitaxial BiFeO3 multiferroic thin film heterostructures [J]. Science, 2003, 299: 1719–1722.
[37]
？ LEBEUGLE D, COLSON D, FORGET A et al. Room-temperature coexistence of large electric polarization and magnetic order in BiFeO3 single crystals [J]. Phys Rev B, 2007, 76: 024116.
[38]
？ CHU Y H, ZHAO T, CRUZ M P, et al. Ferroelectric size effects in multiferroic BiFeO3 thin films [J]. Appl Phys Lett, 2007, 90: 252906.
[39]
？ CHOI T, LEE S, CHOI Y J, et al. Switchable ferroelectric diode and photovoltaic effect in BiFeO3 [J]. Science, 2009, 324: 63–66.
[40]
？ YANG S Y, SEIDEL J, BYRNES S J, et al. Above-bandgap voltages from ferroelectric photovoltaic devices [J]. Nat Nanotechnol, 2010, 5: 143–147.
[41]
？ YU P, LEE J S, OKAMOTO S, et al. Interface ferromagnetism and orbital reconstruction in BiFeO3–La0.7Sr0.3MnO3 heterostructures [J]. Phys Rev Lett, 2010, 105: 027201.
[42]
？ YU P, CHU Y H, RAMESH R. Oxide interfaces: pathways to novel phenomena [J]. Mater Today, 2012, 15: 320–327.
[43]
？ TEAGUE J R, GERSON R, JAMES W J. Dielectric hysteresis in single crystal BiFeO3 [J]. Solid State Commun, 1970, 8: 1073–1074.
[44]
？ SMOLENSKII G A, AGRANOVSKA Y A, ISUPOV V A, et al. New ferroelectrics of complex composition: Pb2MgWO6, Pb3Fe2WO9 and Pb2FeTaO6 [J]. SOVIET PHYSICS-SOLID STATE, 1958, 3: 1981–1983.
[45]
？ KACZMAREK W, PAJAK Z, POLOMSK A M. Differential thermal analysis of phase transitions in (Bi1？xLax)FeO3 solid solution [J]. Solid State Commun, 1975, 17: 807–810.
[46]
？ KUMAR M M, PALKAR V R, SRINIVAS K, et al. Ferroelectricity in a pure BiFeO3 ceramic [J]. Appl Phys Lett, 2000, 76: 2764–2766.
[47]
？ NEATON J B, EDERER C, WAGHMARE U V, et al. First-principles study of spontaneous polarization in multiferroic BiFeO3 [J]. Phys Rev B, 2005, 71: 014113; ZAVALICHE F, YANG S Y, ZHAO T, et al, Multiferroic BiFeO3 films: domain structure and polarization dynamics [J]. Phase Transitions, 2006, 79: 991–1017.
[48]
？ YUN K Y, NODA M, OKUYAMA M, et al. Structural and multiferroic properties of BiFeO3 thin films at room temperature [J]. J Appl Phys, 2004, 96: 3399–3403.
[49]
？ JANG H W, BAEK S H, ORTIZ D, et al. Strain-induced polarization rotation in epitaxial (001) BiFeO3 Thin films [J]. Phys Rev Lett, 2008, 101: 107602.
[50]
？ BEA H, DUPE B, FUSIL S, et al. Evidence for room-temperature multiferroicity in a compound with a giant axial ratio [J]. Phys Rev Lett, 2009, 102: 217603.
[51]
？ ZECHES R J, ROSSELL M D, ZHANG J X, et al. A strain-driven morphotropic phase boundary in BiFeO3 [J]. Science, 2009, 326: 977–980.
[52]
？ ZHANG J X, HE Q, MORGAN T, et al. Microscopic origin of the giant ferroelectric polarization in tetragonal-like BiFeO3 [J]. Phys Rev Lett, 2011, 107: 147602.
[53]
？ KUTNJAK Z, PETZELT J, BLINC R. The giant electromechanical response in ferroelectric relaxors as a critical phenomenon [J]. Nature, 2006, 441: 956–959.
[54]
？ CHEN P, SICHEL-TISSOT R J, JO, J Y. et al. Nonlinearity in the high-electric-field piezoelectricity of epitaxial BiFeO3 on SrTiO3 [J]. Appl Phys Lett, 2012, 100: 062906.
[55]
？ ZHANG J X, XIANG B, HE Q, et al. Large field-induced strains in a lead-free piezoelectric material [J]. Nat Nanotechnol, 2011, 6: 98–102.
[56]
？ ZAVALICHE F, SHAFER P, RAMESH R, et al. Polarization switching in epitaxial BiFeO3 films [J]. Appl Phys Lett, 2008, 87: 252902.
[57]
？ CRUZ M P, CHU Y H, ZHANG J X, et al. Strain control of domain-wall stability in epitaxial BiFeO3 (110) films [J]. Phys Rev Lett, 2007, 99: 217601.
[58]
？ BAEK S H, JANG H W, FOLKMAN C M, et al. Ferroelastic switching for nanoscale non-volatile magnetoelectric devices [J]. Nat Mater, 2010, 9: 309–314.
[59]
？ BALKE N, CHOUDHURY S, JESSE S, et al. Deterministic control of ferroelastic switching in multiferroic materials [J]. Nat Nanotechnol, 2009, 4: 868–875.
[60]
？ MAZUMDAR D, SHELKE V, ILIEV M, et al. Nanoscale switching characteristics of nearly tetragonal BiFeO3 thin films [J]. Nano Lett, 2010, 10: 2555–2561.
[61]
？ LEE Y H, WU J, LAI C, et al. Influence of La doping in multiferroic properties of BiFeO3 thin films [J]. Appl Phys Lett, 2006, 88: 042903.
[62]
？ LEE D, KIM M G, RYU S, et al. Epitaxially grown La-modified BiFeO3 magnetoferroelectric thin films [J]. Appl Phys Lett, 2005, 86: 222903.
[63]
？ PABST G W, MARTIN L W, CHU Y H, et al. Leakage mechanisms in BiFeO3 thin films [J]. Appl Phys Lett, 2007, 90: 072902.
[64]
？ WOJDEL J C, INIGUEZ J. Magnetoelectric response of multiferroic BiFeO3 and related materials from first-principles calculations [J]. Phys Rev Lett, 2009, 103: 267205.
[65]
？ YANG H, WANG Y H, WANG H, et al. Oxygen concentration and its effect on the leakage current in BiFeO3 thin films [J]. Appl Phys Lett, 2010, 96: 012909.
[66]
？ ZALESSKII A V, FROLOV A A, ZVEZDIN A K, et al. Effect of spatial spin modulation on the relaxation and NMR frequencies of 57Fe nuclei in a ferroelectric antiferromagnet BiFeO3 [J]. JETP, 2002, 95: 101–105.
[67]
？ RAMAZANOGLU M, RATCLIFF II W, YI H T et al. Giant effect of uniaxial pressure on magnetic domain populations in multiferroic bismuth ferrite [J]. Phys Rev Lett, 2011, 107: 067203.
[68]
？ DE SOUSA R, MOORE J E. Optical coupling to spin waves in the cycloidal multiferroic BiFeO3 [J]. Phys Rev B, 2008, 77: 012406.
[69]
？ DE SOUSA R, MOORE J E. Electrical control of magnon propagation in multiferroic BiFeO3 films [J]. Appl Phys Lett, 2008, 92: 022514.
[70]
？ CAZAYOUS M, GALLAIS Y, SACUTO A, et al. Possible observation of cycloidal electromagnons in BiFeO3 [J]. Phys Rev Lett, 2008, 101: 037601.
[71]
？ ROVILLAIN P, DE SOUSA R, GALLAIS Y, et al. Electric-field control of spin waves at room temperature in multiferroic BiFeO3 [J]. Nat Mater, 2010, 9: 975–979.
[72]
？ TABARES-MUNOZ C, RIVERA J P, BEZINGES A, et al. Measurement of the quadratic magnetoelectric effect on single crystalline BiFeO3 [J]. Jpn J Appl Phys, 1985, 24: 1051–1053.
[73]
？ SOSNOWSKA I, NEUMAIER T P, STEICHELE E, et al. Spiral magnetic ordering in bismuth ferrite [J]. J Phys C, 1982, 15: 4835– 4846.
[74]
？ KADOMTSEVA A M, ZVEZDIN A K, POPOV Y F, et al. Space-time parity violation and magnetoelectric interactions in antiferromagnets [J]. JETP Lett, 2004, 79: 571–581.
[75]
？ RUETTE B, ZVYAGIN S, PYATAKOV A P, et al. Magnetic-field- induced phase transition in BiFeO3 observed by high-field electron spin resonance [J]. Phys Rev B, 2004, 69: 064114.
[76]
？ MURASHOV V A, RAKOV D N, IONOV V M, et al. Magnetoelectric (Bi, Ln)FeO3 compounds: Crystal growth, structure and properties [J]. Ferroelectrics, 1994, 162: 11–21.
[77]
？ SINGH A, PANDEY V, KOTNALA R K, et al. Direct evidence for multiferroic magnetoelectric coupling in 0.9BiFeO3–0.1BaTiO3 [J]. Phys Rev Lett, 2008, 101: 247602.
