Comment on "Critical and slow dynamics in a bulk metallic glass exhibiting strong random magnetic anisotropy" [Appl. Phys. Lett. 92, 011923 (2008)]

TL;DR

This comment clarifies that the observed hysteresis loop shift in a magnetic glass is due to measurement range and time effects, not an intrinsic property, emphasizing the importance of experimental conditions.

Contribution

It demonstrates through Monte Carlo simulations that the hysteresis shift is caused by measurement parameters, not an inherent material property.

Findings

Hysteresis shift depends on the field range and observation time.

Exceeding the reversible field removes the hysteresis shift.

Longer observation times eliminate the shift within the same field range.

Abstract

In this comment, by using Monte Carlo simulation, we show that the perpendicular shift of hysteresis loops reported in the commented work is nothing special but simply due to the fact that the range of field does not surpass the reversible field beyond which the two branches of the loop merge. If the reversible field is exceeded, the shift is no longer observed. Moreover, we point out that even using a small range of field, the shift will not be observed if the observation time is long enough for the reversible field to drop within the range.