The absence of exchange bias with (001)‐oriented tetragonal‐like BiFeO3 films

Single‐phase tetragonal‐like BiFeO3 (T‐BFO) films with thickness up to 480 nm have been successfully prepared on (001) LaAlO3 substrates using NdAlO3 (NAO) as a buffer layer. The monoclinic distortion increases on increasing the thickness of T‐BFO films. Negligible small exchange bias field (HE) (<8 Oe) has been observed in T‐BFO/NiFe bilayers. The insertion of a 2‐nm thick La0.67Sr0.33MnO3 (LSMO) film between NAO and BFO can keep the structure of single‐phase T‐BFO. Strongly enhanced HE and coercivity has been observed below 100 K in LSMO/T‐BFO bilayer, which has been attributed to the phase separation and coexistence of antiferromagnetic and ferromagnetic phases in the ultrathin LSMO layer due to the compressive strain exerted by the NAO buffer layer. Our results clearly demonstrate that T‐BFO cannot provide an effective exchange bias field on the adjacent ferromagnetic layer, and the possible explanation has been provided.

[1]  Qingyu Xu,et al.  Exchange bias in polycrystalline Bi1−xLaxFeO3/NiFe bilayers , 2013 .

[2]  Shiming Zhou,et al.  Temperature dependent exchange bias effect in polycrystalline BiFeO3/FM (FM  =  NiFe, Co) bilayers , 2013 .

[3]  Hong-Ji Lin,et al.  Orthorhombic BiFeO 3 , 2012 .

[4]  P. Mukherjee,et al.  Influence of microstructure and interfacial strain on the magnetic properties of epitaxial Mn3O4/La0.7Sr0.3MnO3 layered-composite thin films , 2012 .

[5]  I. Fina,et al.  Dielectric response of epitaxially strained CoFe2O4 spinel thin films , 2012 .

[6]  F. Bai,et al.  Strong exchange bias with the (110)-oriented BiFeO3 films , 2012 .

[7]  Zuhuang Chen,et al.  Suppression of mixed-phase areas in highly elongated BiFeO3 thin films on NdAlO3 substrates , 2012 .

[8]  Qingyu Xu,et al.  The exchange bias in polycrystalline BiFeO3/Ni81Fe19 bilayers on Si substrate with LaNiO3 buffer layer , 2012 .

[9]  Jin Hong Lee,et al.  Concurrent transition of ferroelectric and magnetic ordering near room temperature. , 2011, Nature communications.

[10]  Lane W. Martin,et al.  Temperature and thickness evolution and epitaxial breakdown in highly strained BiFeO 3 thin films , 2011, 1110.3847.

[11]  D. Dekadjevi,et al.  Experimental evidence for exchange bias in polycrystalline BiFeO3/Ni81Fe19 thin films , 2011 .

[12]  C H Wang,et al.  Microscopic origin of the giant ferroelectric polarization in tetragonal-like BiFeO(3). , 2011, Physical review letters.

[13]  E. Dagotto,et al.  Antiferromagnetic transitions in `tetragonal-like' BiFeO3 , 2011, 1107.2975.

[14]  A. Senyshyn,et al.  Simultaneous changes of nuclear and magnetic structures across the morphotropic phase boundary in (1−x)BiFeO3−xPbTiO3 , 2010 .

[15]  M D Rossell,et al.  Reversible electric control of exchange bias in a multiferroic field-effect device. , 2010, Nature materials.

[16]  M. J. Lee,et al.  Interface ferromagnetism and orbital reconstruction in BiFeO3-La(0.7)Sr(0.3)MnO3 heterostructures. , 2010, Physical review letters.

[17]  Sergei V. Kalinin,et al.  Nanoscale switching characteristics of nearly tetragonal BiFeO3 thin films. , 2010, Nano letters.

[18]  A. Mougin,et al.  Electric field switching of the magnetic anisotropy of a ferromagnetic layer exchange coupled to the multiferroic compound BiFeO3. , 2009, Physical review letters.

[19]  R. Ramesh,et al.  A Strain-Driven Morphotropic Phase Boundary in BiFeO3 , 2009, Science.

[20]  K. Bouzehouane,et al.  Coengineering of ferroelectric and exchange bias properties in BiFeO3 based heterostructures , 2009 .

[21]  N. Spaldin,et al.  Strain-induced isosymmetric phase transition in BiFeO 3 , 2009, 0909.4979.

[22]  Zhifeng Ren,et al.  Multiferroicity: the coupling between magnetic and polarization orders , 2009, 0908.0662.

[23]  V. Cros,et al.  Evidence for room-temperature multiferroicity in a compound with a giant axial ratio. , 2009, Physical review letters.

[24]  C. Xiong,et al.  Electric and magnetic modulation of fully strained dead layers in La(0.67)Sr(0.33)MnO(3) films , 2008 .

[25]  M. Bibes,et al.  Multiferroics: towards a magnetoelectric memory. , 2008, Nature materials.

[26]  Shan X. Wang,et al.  Nanoscale control of exchange bias with BiFeO3 thin films. , 2008, Nano letters.

[27]  Zhenxiang Cheng,et al.  Structure, ferroelectric properties, and magnetic properties of the La-doped bismuth ferrite , 2008 .

[28]  K. Bouzehouane,et al.  Mechanisms of exchange bias with multiferroic BiFeO3 epitaxial thin films. , 2007, Physical review letters.

[29]  A. Fert,et al.  Tunnel junctions with multiferroic barriers. , 2007, Nature materials.

[30]  T. Zhao,et al.  Electrical control of antiferromagnetic domains in multiferroic BiFeO3 films at room temperature , 2006, Nature materials.

[31]  M. Blamire,et al.  Large Electric Polarization and Exchange Bias in Multiferroic BiFeO3 , 2006 .

[32]  N. Spaldin,et al.  Weak ferromagnetism and magnetoelectric coupling in bismuth ferrite , 2004, cond-mat/0407003.

[33]  E Steichele,et al.  Spiral magnetic ordering in bismuth ferrite , 1982 .