Magnetic and Static Nonlinear Dielectric Response in Doped CdCr₂S₄

Abstract

The influence of cation substitution on the magnetic and static nonlinear dielectric response in the doped magnetic relaxor ferroelectrics CdCr₂S₄ is investigated within the framework of the spherical random-bond-random-field model (SRBRF) and the site-dilution Heisenberg model by adding an appropriate coupling term between the magnetic and ferroelectric subsystems. A-site substitution of the Cd by Fe in Cd_1-xFe_xCr₂S₄ is found to reduce significantly the magnetization, which well agrees with the experimental results. Furthermore, the doping Fe ions play a crucial role in the spin-pair correlation and the nonlinear dielectric properties.

Keywords:

• Magnetic relaxor ferroelectrics
• nonlinear dielectric response

Classification codes:

• 75.50.Gg
• 75.80.+q
• 77.80.Bh

Acknowledgments

This work was supported by the National Natural Science Foundation of China under Grant Nos. 10474069, 50832002 and 10904101, and the Natural Science Foundation of JiangSu Education Committee of China under Grant No. 08KJB140006.