High frequency magneto-impedance of double perovskite $La_{1.2}Sr_{1.8}Mn_{2}O_{7}$: secondary transitions at high temperatures

TL;DR

This study investigates the radio frequency magneto-impedance behavior of the double perovskite $La_{1.2}Sr_{1.8}Mn_{2}O_{7}$, revealing a high-temperature anomaly linked to short-range magnetic correlations not evident in static measurements.

Contribution

It uncovers a high-temperature magnetic anomaly in $La_{1.2}Sr_{1.8}Mn_{2}O_{7}$ using radio frequency measurements, highlighting dynamic magnetic correlations beyond static analysis.

Findings

Anomaly at 260K observed in RF magneto-impedance

Main MI transition at 125K identified in static measurements

Short-range magnetic correlations enhanced at radio frequencies

Abstract

Radio frequency magneto-impedance measurements clearly reveal a pronounced anomaly at 260K besides the main MI transition at 125K in the double perovskite material $La_{1.2}Sr_{1.8}Mn_{2}O_{7}$. This feature is not seen clearly in static resistivity and magnetization measurements. We suggest that this anomaly represents short range magnetic correlations enhanced at radio frequencies, with the easy axis along the c-axis .