Magnetoelectric properties of quantum paraelectric EuTiO3 materials on the strain effect

Abstract

Because of the strong coupling between the magnetic and dielectric properties, the study of quantum paraelectric EuTiO3 has attracted more and more attention in both theoretical and experimental research recently. In this paper, the first principles based on the density functional theory within the generalized gradient approxiamtion is used to investigate the magnetic and electronic structure of quantum paraelectric EuTiO3, and to analyze the effects of the strain on the magnetic and strutural phase transition, in turn to discuss the possible magnetoelectric coupling mechanism of this material. The calculations show that EuTiO3 with the strain-free is in a paraelectric cubic and G-type antiferromagnetic state at low temperature, while appling either compressive or tensile strain along the c-axis to it, the balance of hybridization between Ti 3d and O 2p orbit will be breaken and EuTiO3 will transite from paraelectric and G-antiferromagnetic to ferroelectric-ferromagnetic structure as the strain is increased to a certain value. All those indicate the strong spin-lattice coupling effect in EuTiO3.

Possible magnetic structures of EuZrO 3

“…Note that the χ(T GN ) and Θ G values are always equal to 1.62462 and 0.1 K based on experimental measurements. [4] Following this procedure, the relation among T GN , J 2 , and D is plotted in Fig. 2.…”

“…Multiferroics with magnetoelectric properties have recently become the focus of intensive research due to the coexistence of both magnetic and electric ordering parameters, which is of interest for novel exciting applications like magnetic field sensors, tunable microwave devices, multiple state memory elements, and spintronic devices. [1][2][3][4][5] For their practical applications, detailed knowledge about their crystal structures and magnetic structures is necessary.…”