Pinning dependent field driven domain wall dynamics and thermal scaling in an ultrathin Pt/Co/Pt magnetic film

TL;DR

This study investigates magnetic domain wall motion in ultrathin Pt/Co/Pt films across various temperatures, identifying distinct dynamical regimes and confirming theoretical predictions for thermal effects and pinning behavior.

Contribution

It provides a detailed experimental analysis of domain wall dynamics, pinning regimes, and thermal scaling in ultrathin ferromagnetic films, with results aligning with numerical models.

Findings

Identification of creep, flux flow, and depinning regimes

Determination of elastic energy and pinning parameters

Thermal exponents match numerical predictions

Abstract

Magnetic field-driven domain wall motion in an ultrathin Pt/Co(0.45nm)/Pt ferromagnetic film with perpendicular anisotropy is studied over a wide temperature range. Three different pinning dependent dynamical regimes are clearly identified: the creep, the thermally assisted flux flow and the depinning, as well as their corresponding crossovers. The wall elastic energy and microscopic parameters characterizing the pinning are determined. Both the extracted thermal rounding exponent at the depinning transition, $\psi=$0.15, and the Larkin length crossover exponent, $\phi=$0.24, fit well with the numerical predictions.