Memory effects in permalloy-niobium hybrid structures

TL;DR

This study investigates how superconducting niobium influences magnetic domain structures and memory effects in permalloy-niobium hybrid nanofilms across a wide temperature range, revealing a superconducting memory phenomenon that is reset by heating above T_c.

Contribution

It demonstrates the existence of a superconducting memory effect in permalloy-niobium hybrids and explores how niobium affects magnetic domain structures via interface quality and stray field distortion.

Findings

Niobium influences magnetic domain wall types and structures.

A superconducting memory effect is observed, retaining initial magnetic states below T_c.

Memory is erased by heating above T_c.

Abstract

The kineticts of magnetization reversal of stripe-shaped permalloy-niobium hybrid nanofilms is studied in 6-300 K temperature range by means of magneto-optics visualization technique. The niobium influence on magnetic domain walls type and on magnetic domain structure of permalloy via the interface quality and via the distortion of stray fields is found. The memory effect, which is the superconducting niobium memory about an initial magnetic domain structure of permalloy at cooling below T_c, is found. The memory is razed only by hybrid heating over T_c.