Modulated structure and physical properties of MnWO4 ceramics via Zr4+ replacement

Abstract

Ceramic samples of Mn1-xZrxWO4 (0.00 ≤ x ≤ 0.20) were prepared by a solid-state reaction to study changes in the structural, magnetic, and dielectric properties of multiferroic MnWO4 caused by replacing Mn2+ ions with Zr4+ ions. The results indicate that Zr4+ replacement caused lattice deformation but did not affect the monoclinic lattice structure of any of the MnWO4 samples. The concentration of vacancies, investigated by positron annihilation lifetime spectroscopy, increased with as the Zr4+ content x from 0.00 to 0.20. It was observed that Zr4+ replacement enhanced the dielectric constant of Mn1-xZrxWO4 but slightly increased the dielectric loss. The magnetization and transition temperatures (TAF3 and TAF2) of the Mn1-xZrxWO4 system were increased by the Zr4+ replacement, and the existing temperature range of the AF2 phase was extended upon the substitution of Zr4+ for Mn2+. This study demonstrated that the magnetic properties of Mn1-xZrxWO4 were closely related to the vacancy concentration and lattice distortion.