Magnetism driven ferroelectricity above liquid nitrogen temperature in Y2CoMnO6

Abstract

We report multiferroic behavior in double perovskite Y 2 CoMnO 6 with ferroelectric transition temperature T c = 80K. The origin of ferroelectricity is associated with magnetic ordering of Co 2+ and Mn 4+ moments in a ↑↑-↓↓ arrangement. The saturation polarization and magnetization are estimated to be 65 µC/m 2 and 6.2 µ B /f.u. respectively. The magnetoelectric coupling parameter, on the other hand, is small as a 5 Tesla field suppresses the electric polarization by only ~8%. This is corroborated with observed hysteretic behaviour at 5K that remains unsaturated even upto 7 Tesla. A model based on exchange-striction is proposed to explain the observed high temperature ferroelectricity. a) spatnaik@mail.jnu.ac.in

Metamagnetic behaviour and effect of field cooling on sharp magnetization jumps in multiferroic Y 2 CoMnO 6

“…1(b)), and the metamagnetic phase transition from E*-type AFM to FM state is the first order in nature. The first order metamagnetic phase transition in YCMO indicates the phase coexistence of E*-AFM and FM phases and this complements Sharma et al work, where magnetic inhomogeneity was probed by neutron diffraction [24]. Though metamagnetic behaviour is present up to 10 K, the abrupt nature of field induced transition is apparent only below 4.6 K as shown in Fig.…”

“…Experimental results and discussion.-Polycrystalline YCMO sample was prepared by conventional solid state method, crystal structure, and lattice parameters obtained from the Rietveld refinement match well with the previous report (monoclinic crystal structure with space group P 2 1 /n and crystallographic parameters: a = 5.233 Å, b = 5.590 Å, c = 7.470 Å and β = 89.948°) [24]. Temperature and magnetic field dependence of dc susceptibility measurements were done by Quantum Design SQUID-VSM magnetometer.…”

“…Recently, improper magnetic multiferroicity was predicated in Y 2 NiMnO 6 and found experimentally in Lu 2 CoMnO 6 and Y 2 CoMnO 6 (YCMO) double perovskite systems, where the E*-type AFM ordering with collinear ↑↑↓↓ spin structure breaks the spatial inversion symmetry and leads to the spontaneous polarization [22,23,24]. Such simultaneous existence of both AFM and ferroelectric ordering is of significant interest in data storage and spintronic applications [25,26].…”

The ferroelectric polarization of Y2CoMnO6aligns along the b-axis: the first-principles calculations

“…47 The estimated TN = 79 K is in good agreement with experimental temperature 80 K at which the spontaneous polarization first emerges. 25 …”

Improper ferroelectricity in helicoidal antiferromagnet Cu3Nb2O8

“…Ca 3 CoMnO 6 , Y 2 CoMnO 6 ) and non-collinear (e.g. MnWO 4 , TbMnO 3 , Ni 3 V 2 O 8 ) magnetic ordering can lead to such juxtaposition of mutually exclusive material properties [3][4][5][6][7][8]. But the microscopic reason could be quite different.…”