Noncollinear phase of TbDy alloys
Abstract
Tb{sub {ital x}}Dy{sub 1{minus}{ital x}} is probably the simplest example of a magnetic system with competing anisotropy. Tb and Dy are both lowtemperature easyplane ferromagnets with wellcharacterized anisotropy energies, such that Tb moments prefer the {bold b} axis in the hcp structure, while Dy moments prefer the {bold a} axis. It has been predicted, by a twosubnetwork approximation, that the lowtemperature phase of the alloys with {ital x} between 0.86 and 0.76 exhibits a nonsymmetry direction of magnetization, a noncollinear spin structure, and 12thorder anisotropy. However, the twosubnetwork approximation is suspect when used to describe magnetic structure in alloys near phase boundaries, such as those between the ferromagnetic and the noncollinear phase. Using a probability distribution for site occupation, we have calculated the fluctuations of the spin orientation and the spinspin correlation function as a function of composition in the noncollinear phase. The meansquare fluctuation in spin orientation is proportional to ({ital x}{sub {ital b}}{minus}{ital x}){sup 1/2}, where {ital x}{sub {ital b}} is the critical concentration which separates the {bold b} axis ferromagnet from the noncollinear magnet. The average orientation also varies as ({ital x}{sub {ital b}}{minus}{ital x}){sup 1/2}. Therefore, the simple twosubnetwork model is not valid near the phasemore »
 Authors:

 Physics Department, The American University, Washington, DC 20016 (USA)
 Solid State Branch (R45), Naval Surface Warfare Center, White Oak, Maryland 209035000 (USA)
 Publication Date:
 OSTI Identifier:
 7123536
 Resource Type:
 Journal Article
 Journal Name:
 Journal of Applied Physics; (USA)
 Additional Journal Information:
 Journal Volume: 67:9; Journal ID: ISSN 00218979
 Country of Publication:
 United States
 Language:
 English
 Subject:
 36 MATERIALS SCIENCE; DYSPROSIUM ALLOYS; MAGNETIC PROPERTIES; TERBIUM ALLOYS; ANISOTROPY; CORRELATIONS; FLUCTUATIONS; QUANTITY RATIO; SPIN; SPIN ORIENTATION; ALLOYS; ANGULAR MOMENTUM; ORIENTATION; PARTICLE PROPERTIES; PHYSICAL PROPERTIES; RARE EARTH ALLOYS; VARIATIONS; 360104*  Metals & Alloys Physical Properties
Citation Formats
Foster, J J, and Cullen, J R. Noncollinear phase of TbDy alloys. United States: N. p., 1990.
Web. doi:10.1063/1.346037.
Foster, J J, & Cullen, J R. Noncollinear phase of TbDy alloys. United States. https://doi.org/10.1063/1.346037
Foster, J J, and Cullen, J R. Tue .
"Noncollinear phase of TbDy alloys". United States. https://doi.org/10.1063/1.346037.
@article{osti_7123536,
title = {Noncollinear phase of TbDy alloys},
author = {Foster, J J and Cullen, J R},
abstractNote = {Tb{sub {ital x}}Dy{sub 1{minus}{ital x}} is probably the simplest example of a magnetic system with competing anisotropy. Tb and Dy are both lowtemperature easyplane ferromagnets with wellcharacterized anisotropy energies, such that Tb moments prefer the {bold b} axis in the hcp structure, while Dy moments prefer the {bold a} axis. It has been predicted, by a twosubnetwork approximation, that the lowtemperature phase of the alloys with {ital x} between 0.86 and 0.76 exhibits a nonsymmetry direction of magnetization, a noncollinear spin structure, and 12thorder anisotropy. However, the twosubnetwork approximation is suspect when used to describe magnetic structure in alloys near phase boundaries, such as those between the ferromagnetic and the noncollinear phase. Using a probability distribution for site occupation, we have calculated the fluctuations of the spin orientation and the spinspin correlation function as a function of composition in the noncollinear phase. The meansquare fluctuation in spin orientation is proportional to ({ital x}{sub {ital b}}{minus}{ital x}){sup 1/2}, where {ital x}{sub {ital b}} is the critical concentration which separates the {bold b} axis ferromagnet from the noncollinear magnet. The average orientation also varies as ({ital x}{sub {ital b}}{minus}{ital x}){sup 1/2}. Therefore, the simple twosubnetwork model is not valid near the phase boundaries. In fact, we find that the fluctuations from the average site occupation increase the range of stability of the noncollinear phase.},
doi = {10.1063/1.346037},
url = {https://www.osti.gov/biblio/7123536},
journal = {Journal of Applied Physics; (USA)},
issn = {00218979},
number = ,
volume = 67:9,
place = {United States},
year = {1990},
month = {5}
}