Enhancement of ferroelectricity in Cr-doped Ho_2Ti_2O_7

TL;DR

This study demonstrates that Cr doping in Ho2Ti2O7 significantly enhances its ferroelectric polarization and transition temperature, revealing multiferroic properties in the doped pyrochlore material.

Contribution

The paper reports a novel doping strategy that markedly increases ferroelectricity and transition temperature in Ho2Ti2O7, indicating potential for multiferroic applications.

Findings

Polarization increased to 660 μC/m2 at x=0.4

Ferroelectric transition temperature raised to ~140K

Evidence of multiferroic behavior through magnetic anomaly

Abstract

A series of polycrystalline pyrochlore rare-earth titanate Ho_{2-x}Cr_xTi_2O_7 are synthesized in order to enhance the ferroelectricity of pyrochlore Ho2Ti2O7. For the sample close to the doping level x=0.4, a giant enhancement of polarization P up to 660\muC/m2 from 0.54\muC/m2 at x=0 is obtained, accompanied with an increment of ferroelectric transition point Tc up to ~140K from ~60K. A magnetic anomaly at T~140K together with the polarization response to magnetic field, is identified, implying the multiferroic effect in Ho2-xCrxTi2O7.