Frequency dependence of dielectric anomaly around Neel temperature in bilayer manganite Pr(Sr0.1Ca0.9)2Mn2O7

TL;DR

This study reports a unique frequency-dependent dielectric anomaly near the Neel temperature in a bilayer manganite, revealing intrinsic capacitive behavior and temperature shifts over a broad frequency range.

Contribution

It uncovers a novel frequency dependence of dielectric anomalies around T_N in Pr(Sr0.1Ca0.9)2Mn2O7, highlighting intrinsic capacitive effects.

Findings

Dielectric anomaly shifts within ~40 K around T_N across frequencies

Anomaly occurs at T_f, moving with frequency in 50 kHz-5 MHz range

Capacitive component shows broad feature confirming intrinsic response

Abstract

A novel frequency dependence of anomaly in dielectric constant versus temperature plot, around the Neel temperature T_N (~150 K), has been observed in a single crystal of bilayer manganite Pr(Sr0.1Ca0.9)2Mn2O7. The anomaly in the permittivity (epsilon'||c) occurs at a temperature T_f which moves within a temperature window (delT_f) of ~40 K around T_N for a frequency range 50 kHz-5 MHz. The capacitive component Cp of the dielectric response exhibits a clear yet broad feature around T_N which establishes the intrinsic capacitive nature of the anomaly.