Multiple slow relaxation of magnetization in Dy confined in the crystal matrix of rare-earth-calcium silicates with the apatite structure

Apatite-type silicates Y 7.75 Dy 0.25 Ca 2 (SiO 4 ) 6 O 2 and Dy 8 Ca 2 (SiO 4 ) 6 O 2 were prepared by high-temperature solid state synthesis. In the crystal lattice, Dy 3+ partially substitutes Ca 2+ , preferably at the 6h Ca2-site, and forms a short bond of 2.2 Å with the intra-channel O 2− . The...

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Bibliographic Details
Published in:Dalton transactions : an international journal of inorganic chemistry 2020-02, Vol.49 (6), p.214-223
Main Authors: Kazin, Pavel E, Zykin, Mikhail A, Trusov, Lev A, Vasiliev, Alexander V, Kremer, Reinhard K, Dinnebier, Robert E, Jansen, Martin
Format: Article
Language:English
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Summary:Apatite-type silicates Y 7.75 Dy 0.25 Ca 2 (SiO 4 ) 6 O 2 and Dy 8 Ca 2 (SiO 4 ) 6 O 2 were prepared by high-temperature solid state synthesis. In the crystal lattice, Dy 3+ partially substitutes Ca 2+ , preferably at the 6h Ca2-site, and forms a short bond of 2.2 Å with the intra-channel O 2− . The imposed strong ligand field anisotropy provides large magnetic anisotropy, which manifests itself as slow relaxation of magnetization at low temperatures. The magnetic dynamics is characterized by three or two characteristic values of relaxation time, respectively, which may be attributed to a single Dy 3+ center. A phenomenological model is proposed which explains this response in terms of single paramagnetic center multiple relaxation. Dy 3+ reveals slow relaxation of magnetization in both Dy-diluted and Dy-rich silicates with enhanced relaxation times in the latter.
ISSN:1477-9226
1477-9234
DOI:10.1039/c9dt04248b