Mechanism of temperature dependence of the magnetic anisotropy energy in ultrathin Cobalt and Nickel films

TL;DR

This paper investigates how temperature affects magnetic anisotropy energy in ultrathin Co and Ni films, revealing magnon excitations as the sole cause of its reduction with increasing temperature.

Contribution

It introduces a microscopic theory explaining the temperature dependence of magnetic anisotropy energy in ultrathin metallic films, focusing on magnon excitations.

Findings

Magnetic anisotropy energy decreases with temperature.

Magnon excitations are the sole mechanism for this reduction.

The theory aligns with FMR measurement data.

Abstract

Temperature dependent FMR-measurements of Ni and Co films are analysed using a microscopic theory for ultrathin metallic systems. The mechanism governing the temperature dependence of the magnetic anisotropy energy is identified and discussed. It is reduced with increasing temperature. This behavior is found to be solely caused by magnon excitations.