Faculty Publications

Title

Magnetic behavior of melt-spun gadolinium

Document Type

Article

Journal/Book/Conference Title

Physical Review B - Condensed Matter and Materials Physics

Volume

77

Issue

18

Abstract

Melt-spun Gd is a structurally inhomogeneous system consisting of crystalline grains with an average size of 24±3 nm that are separated by an amorphous interphase. This system exhibits a depression of TC (289.70±0.01 K) relative to bulk Gd (293 K). The effective critical exponents (βeff =0.389±0.017, γeff =1.300±0.014, and δ=4.32±0.02) and critical amplitudes indicate that for the reduced-temperature range in this work, the paramagnetic-to-ferromagnetic transition is consistent with the isotropic dipolar universality class shown by bulk Gd. There is, however, evidence of enhanced anisotropy in the critical behavior of ms-Gd. Increasing random anisotropy in the intergrain regions with decreasing temperature below TC diminishes the coupling between the ferromagnetically ordered grains and produces a previously unobserved low-temperature peak in the imaginary part of the ac susceptibility. The random-anisotropy model provides a good description of the approach to saturation, which may result from the ferromagnetic correlation length becoming comparable to the anisotropy correlation length in the strong-field regime of the model. © 2008 The American Physical Society.

Original Publication Date

5-14-2008

DOI of published version

10.1103/PhysRevB.77.184415

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