Anomalous specific heat and magnetic properties of TmxDy1-xAl2 (0 ≤ x ≤ 1) Pathak, Arjun Bonilla, C. M. Paudyal, Durga Mudryk, Yaroslav Pecharsky, Vitalij
dc.contributor.department Ames Laboratory
dc.contributor.department Materials Science and Engineering 2019-09-13T02:31:24.000 2020-06-29T23:22:32Z 2020-06-29T23:22:32Z 2019-09-28 2018-09-28
dc.description.abstract <p>We study crystal structure, phase transitions and magnetism of pseudo-binary TmxDy1-xAl2 (0 ≤ x ≤ 1) compounds using temperature dependent X-ray powder diffraction, specific heat and magnetization measurements, first principles, and model calculations. In low external magnetic fields, Dy-rich compounds undergo continuous, second-order phase transitions at the respective Curie temperatures, TC. In contrast, the Tm-rich compounds exhibit discontinuous, first-order anomalies in the magnetically ordered states. These sharp transitions correlate with a substantial energy difference between the room temperature cubic and ground state rhombohedral structures of TmAl2. A clear anomaly in the lattice parameter is observed at ∼30 K for x = 0.5, which nearly coincides with TC = 31.2 K. The effective quadrupolar moment of the lanthanides changes sign around x = 0.5, which leads to a nearly zero anisotropy constant and approximately spherical effective 4f charge densities, providing an explanation for the lack of structural distortions below TC for x = 0.5. The calculations confirm [001] as the easy magnetization axis in the ground state tetragonal structure of DyAl2, and reveal collapse of the orbital magnetic moment when the easy magnetization direction changes to [111]. Within the rhombohedral ground state of TmAl2 [111] is the easy magnetization direction.</p>
dc.identifier archive/
dc.identifier.articleid 1370
dc.identifier.contextkey 14909704
dc.identifier.s3bucket isulib-bepress-aws-west
dc.identifier.submissionpath ameslab_manuscripts/356
dc.language.iso en
dc.relation.ispartofseries IS-J 9785
dc.source.bitstream archive/|||Fri Jan 14 23:45:27 UTC 2022
dc.source.uri 10.1016/j.jallcom.2018.09.365
dc.subject.disciplines Materials Science and Engineering
dc.subject.disciplines Metallurgy
dc.subject.keywords Specific heat
dc.subject.keywords Rare earth
dc.subject.keywords First-order-phase-transition
dc.subject.keywords Lanthanoids
dc.title Anomalous specific heat and magnetic properties of TmxDy1-xAl2 (0 ≤ x ≤ 1)
dc.type article
dc.type.genre article
dspace.entity.type Publication
relation.isOrgUnitOfPublication 25913818-6714-4be5-89a6-f70c8facdf7e
relation.isOrgUnitOfPublication bf9f7e3e-25bd-44d3-b49c-ed98372dee5e
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