Room Temperature Ferrimagnetism, Magnetodielectric and Exchange Bias Effect in CoFeRhO${}_4$

Abstract

Geometrically frustrated structures combined with competing exchange interactions that have different magnitudes are known ingredients for achieving exotic properties. Herein, we studied detailed structural, magnetic, thermal (specific heat), magneto-dielectric, and magnetic exchange bias properties of a mixed 3d - 4d spinel oxide with composition CoFeRhO${}_4$. Detailed magnetization, heat capacity, and neutron powder diffraction studies (NPD) highlight long-range ferrimagnetic ordering with an onset at 355 K. The magnetic structure is established using a ferrimagnetic model (collinear-type) that has a propagation vector k = 0, 0, 0. The magneto-dielectric effect appears below the magnetic ordering temperature, and the exchange bias (EB) effect is observed in field cooled (FC) conditions below 355 K. The magneto-dielectric coupling in CoFeRhO${}_4$ originates due to the frustration in the structure, collinear ferrimagnetic ordering, and uncompensated magnetic moments. The unidirectional anisotropy resulting from the uncompensated magnetic moments causes the room-temperature exchange bias effect. Remarkably, the appearance of technologically important properties (ferromagnetism, magnetodielectric effect, and EB) at room temperature in CoFeRhO${}_4$ indicates its potential use in sensors or spintronics.

8 pages, 11 Figures

References in corpus (8)

• Design of compensated ferrimagnetic Heusler alloys for giant tunable exchange bias
• Order by disorder and spiral spin liquid in frustrated diamond lattice antiferromagnets
• Quantum spin liquids in frustrated spin-1 diamond antiferromagnets
• Spin order and dynamics in the diamond-lattice Heisenberg antiferromagnets CuRh2O4 and CoRh2O4
• Polyhedral distortions and unusual magnetic order in spinel FeMn${}_2$O${}_4$
• Dynamic Spin Fluctuations in the Frustrated A-site Spinel CuAl2O4
• Room Temperature Magnetoresistance and Exchange Bias in "314 - type" Oxygen-Vacancy Ordered SrCo${}_{0.85}$Fe${}_{0.15}$O${}_{2.62}$
• Electronic structure of the frustrated diamond lattice magnet NiRh${}_2$O${}_4$