Field-induced vortex-like textures as a probe of the critical line in reentrant spin glasses

Field-induced vortex-like textures as a probe of the critical line in reentrant spin glasses

Martin, N. (Université Paris-Saclay, Paris)
Bannenberg, L.J. (TU Delft Instrumenten groep; TU Delft RST/Storage of Electrochemical Energy)
Deutsch, M. (Lorraine University)
Pappas, C. (TU Delft RST/Neutron and Positron Methods in Materials)
Chaboussant, G. (Université Paris-Saclay, Paris)
Cubitt, R. (Institut Laue-Langevin)
Mirebeau, I. (Université Paris-Saclay, Paris)

2021

We study the evolution of the low-temperature field-induced magnetic defects observed under an applied magnetic field in a series of frustrated amorphous ferromagnets (Fe_1-xMn_x)₇₅P₁₆B₃Al₃ (“a-Fe_1-xMn_x”). Combining small-angle neutron scattering and Monte Carlo simulations, we show that the morphology of these defects resemble that of quasi-bidimensional spin vortices. They are observed in the so-called “reentrant” spin-glass (RSG) phase, up to the critical concentration x_C≈ 0.36 which separates the RSG and “true” spin glass (SG) within the low temperature part of the magnetic phase diagram of a-Fe_1−xMn_x. These textures systematically decrease in size with increasing magnetic field or decreasing the average exchange interaction, and they finally disappear in the SG sample (x= 0.41), being replaced by field-induced correlations over finite length scales. We argue that the study of these nanoscopic defects could be used to probe the critical line between the RSG and SG phases.

http://resolver.tudelft.nl/uuid:16d678d1-1528-4eb6-8315-ed519e3fdff8

https://doi.org/10.1038/s41598-021-99860-2

2045-2322

Scientific Reports, 11 (1)

Institutional Repository

journal article

© 2021 N. Martin, L.J. Bannenberg, M. Deutsch, C. Pappas, G. Chaboussant, R. Cubitt, I. Mirebeau