Magnetic hysteresis behavior of granular manganite La$_{0.67}$Ca$_{0.33}$MnO$_3$ nanotubes

TL;DR

This study investigates the magnetic hysteresis properties of La$_{0.67}$Ca$_{0.33}$MnO$_3$ nanotubes using experimental measurements and micromagnetic simulations to understand their ferromagnetic behavior across temperatures.

Contribution

It combines experimental hysteresis measurements with micromagnetic modeling to quantitatively analyze the magnetic properties of manganite nanotubes.

Findings

Determined coercive fields, saturation, and remanent magnetizations.

Validated a simple ferromagnetic model with micromagnetic simulations.

Analyzed temperature dependence of magnetic parameters.

Abstract

A silicon micromechanical torsional oscillator is used to measure the hysteresis loops of two manganite La_0.67Ca_0.33MnO_3 nanotubes at different temperatures, applying an external field along its main axes. These structures are composed of nanograins with a ferromagnetic core surrounded by a dead layer. Micromagnetic calculations based on the stochastic Landau-Lifshitz-Gilbert equation, are performed to validate a simple model that allows for quantitatively describing the ferromagnetic behavior of the system. Further simulations are used to analyze the experimental data more in depth and to calculate the coercive field, the saturation and remanent magnetizations, and the effective magnetic volume for single nanotubes, over a wide temperature range.