Room-Temperature Type-II Multiferroic Phase Induced by Pressure in Cupric Oxide

Abstract

According to previous theoretical work, the binary oxide CuO can become a room temperature multiferroic via tuning of the superexchange interactions by application of pressure. Thus far, however, there has been no experimental evidence for the predicted room-temperature multiferroicity.Here, we show by neutron diffraction that the multiferroic phase in CuO reaches 295 K with the application of 18.5 GPa pressure. We also develop a spin Hamiltonian based on density functional theory and employing superexchange theory for the magnetic interactions, which can reproduce the experimental results. The present study provides a stimulus to develop room-temperature multiferroic materials by alternative methods based on existing low temperature compounds, such as epitaxial strain, for tunable multifunctional devices and memory applications.

Anhydrous copper tellurite disulfate Cu3TeO3(SO4)2 featuring the coexistence of spin singlets and a long-range antiferromagnetic order

“…Notably, a strong coupling of electric and magnetic subsystems is expected for the chiral magnets. 16,17…”

An additional simultaneous magnetic ordering and magneto-capacitive behavior with dielectric relaxation besides multiferroicity in Fe 1−x Te x VO4

“…This type of multiferroics exhibit magnetically induced ferroelectricity and they are usually understood through three different frameworks: (i) symmetric spin exchange interaction Π ij (S i .S j ), (ii) antisymmetric spin exchange interaction e ij × (S i × S j ) and (iii) spin-ligand interaction (spin-dependent p-d hybridization) (e il .S i ) 2 e il [1,5]. The magnetoelectric coupling is generally modified by chemical substitutions, strain and external pressure or different extreme conditions [6][7][8][9][10][11][12][13]. The substitution at transition metal (TM) site induces distortions in the lattice and generates competing magnetic interactions, resulting in rich physics in these materials [14][15][16][17][18][19][20][21].…”