Temperature dependence of the switching field distributions in all-perpendicular spin-valve nanopillars

TL;DR

This study investigates how temperature affects the switching field distributions in all-perpendicular spin-valve nanopillars, revealing deviations from classical models and proposing a modified temperature-dependent model for better accuracy.

Contribution

The paper introduces a modified Néel-Brown model incorporating a T^{3/2} dependence to better fit experimental data on temperature-dependent switching in spin-valve nanopillars.

Findings

Switching statistics deviate from the classical Néel-Brown model at various temperatures.

A modified model with T^{3/2} dependence accurately fits the experimental data.

Temperature influences the anisotropy energy and magnetization, affecting switching behavior.

Abstract

We present temperature dependent switching measurements of the Co/Ni multilayered free element of 75 nm diameter spin-valve nanopillars. Angular dependent hysteresis measurements as well as switching field measurements taken at low temperature are in agreement with a model of thermal activation over a perpendicular anisotropy barrier. However, the statistics of switching (mean switching field and switching variance) from 20 K up to 400 K are in disagreement with a N\'{e}el-Brown model that assumes a temperature independent barrier height and anisotropy field. We introduce a modified N\'{e}el-Brown model thats fit the experimental data in which we take a $T^{3/2}$ dependence to the barrier height and the anisotropy field due to the temperature dependent magnetization and anisotropy energy.