Specific heat at low temperatures and magnetic measurements in Nd0.5Sr0.5MnO3 and R0.5Ca0.5MnO3 (Nd, Sm, Dy and Ho) samples

TL;DR

This study investigates the low-temperature specific heat and magnetic properties of various Nd, Sm, Dy, and Ho manganese oxide samples, revealing Schottky-like anomalies and magnetic ordering behaviors.

Contribution

It provides new specific heat and magnetic data for these compounds and highlights the challenges in fitting Schottky anomalies at low temperatures.

Findings

Observed Schottky-like anomalies below 10 K in all samples

Magnetic moments exhibit short-range order at low temperatures

Magnetic transitions consistent with previous reports

Abstract

We studied the magnetization as a function of temperature and magnetic field in the compounds Nd0.5Sr0.5MnO3, Nd0.5Ca0.5MnO3, Sm0.5Ca0.5MnO3, Dy0.5Ca0.5MnO3 and Ho0.5Ca0.5MnO3. Ferromagnetic, antiferromagnetic and charge ordering transition in our samples agreed with previous reports. The intrinsic magnetic moments of Nd3+, Sm3+, Dy3+ and Ho3+ ions experienced a short range order at low temperatures. We also did specific heat measurements with applied magnetic fields between 0 and 9 T and temperatures between 2 and 30 K in all five samples. Below 10 K the specific heat measurements evidenced a Schottky-like anomaly for all samples. However, we could not successfully fit the curves to either a two level nor a distribution of two-level Schottky anomaly.