Magnetoelastic coupling in doped multiferroic YCrO$_{3}$

Recent years have witnessed a renewed interest in ABO$_{3}$ structured perovskites due to possibility of combining ferroelectric and ferromagnetic order parameters in a single phase. Here we show an experimental study on one such material namely YCrO$_{3}$ which shows a phase transition from paramagnetic to a canted antiferromagnetic state at T$_{N}\sim $142K and a ferroelectric transition at T$_{C}\sim $473K. The material has an orthorhombic crystal structure ( S.G.Pbnm) In the present work, we prepared polycrystalline samples of YCr$_{1-z}$X$_{z}$O$_{3}$ (X= V or Ni) by conventional solid-state-reaction method. X-ray diffraction shows the formation of single phase material. DC magnetic measurements exhibit a magnetic transition at T$_{N}\sim $140 K and the presence of magnetic hysteresis below this temperature. Above T$_{N}$, the susceptibility follows the Curie-Weiss law with the corresponding effective magnetic moment $\mu _{eff}$ of 3.75$\mu _{B }$close to the theoretically expected value of 3.87 $\mu _{B.}$ Further, we investigated the magneto-elastic coupling in the material using temperature dependent Raman scattering. We observe 16 phonon modes below Tc. Phonon modes at 145, 403 and 422 cm$^{-1}$ showed pronounced deviation from the expected anharmonic behavior below T$_{N}$, suggesting a spin-phonon coupling below T$_{N}$ Further, we also look at the effect of doping at the Cr site on the magnetoeleastic coupling strength in this material.