Nature of magnetoelectric coupling in corundum antiferromagnet Co4Ta2O9

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS

卷:475

Article

Chaudhary, S.¹  Srivastava, P.¹  Kaushik, S. D.²  Siruguri, V²  Patnaik, S.¹ 

[1] Jawaharlal Nehru Univ, Sch Phys Sci, New Delhi 110067, India

[2] UGC DAE Consortium Sci Res, Mumbai Ctr, 246 C CFB,BARC Campus, Mumbai 400085, India

关键词: Neutron diffraction;    Magnetocapacitance;    Multiferroic materials;    Electric polarization;    Magnetization;   

DOI  :  10.1016/j.jmmm.2018.09.071

来源: Elsevier

【 摘 要 】

We study magnetocapacitance (MC) effect and magnetoelectric (ME) coupling in spin-flop driven antiferromagnet Co4Ta2O9. Powder neutron diffraction data reveal that the magnetic structure corresponds to a non-collinear arrangement along with a non-centrosyrnmetric crystal structure below Neel Temperature. Electric polarization is achieved below Neel temperature only when the sample is cooled in the presence of external magnetic field. The magnetocapacitance data at high magnetic fields are analyzed by phenomenological Ginzburg-landau theory of ferro-electromagnets and it is found that change in dielectric constant is proportional to the square of magnetization. The saturation polarization and magnetoelectric coupling are estimated to be 52 mu C/m(2) and gamma = 1.4 x 10(-3) (emu/g)(-2) respectively at 6 Tesla. Strong magnetoelectric coupling and ferro-electric phase in the anti-ferromagnetic Co4Ta2O9 are correlated to magnetic structure as derived from neutron diffraction data.

【 授权许可】

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