Application of High-Frequency Electron Paramagnetic Resonance/Electron Spin Echo for the Identification of the Impurity Composition and Electronic Structure of Ceramics Based Garnets

• Published in: Physics of the solid state Vol. 61; no. 10; pp. 1820 - 1828
• Main Authors: Edinach, E. V., Uspenskaya, Yu. A., Gurin, A. S., Babunts, R. A., Asatryan, G. R., Romanov, N. G., Badalyan, A. G., Baranov, P. G.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01-10-2019; Springer; Springer Nature B.V
• Subjects: ALUMINIUM; Aluminum; Ceramic materials; CERAMICS; Cerium; CERIUM IONS; CHROMIUM IONS; CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; Electron paramagnetic resonance; Electron spin; ELECTRON SPIN RESONANCE; ELECTRONIC STRUCTURE; Electrons; Ferromagnetism; FINE STRUCTURE; Frequency ranges; Gadolinium; GADOLINIUM COMPLEXES; GADOLINIUM IONS; GARNETS; HIGH SPIN STATES; IMPURITIES; Impurity Centers; LANDE FACTOR; Physics; Physics and Astronomy; Rare earth metals; SIGNALS; Solid State Physics; Spectra; TEMPERATURE DEPENDENCE; YTTERBIUM IONS; YTTRIUM; Yttrium-aluminum garnet; ceramics; electron spin echo; rare-earth ions; electron paramagnetic resonance; transition ions; garnets
• ISSN: 1063-7834; 1090-6460
• DOI: 10.1134/S1063783419100135

Electron paramagnetic resonance (EPR) spectra of Ce
3+
, Yb
3+
, Cr
3+
, and Gd
3+
impurity ions in yttrium aluminum garnet Y
3
Al
5
O
12
(YAG) ceramics were detected and identified at frequency of 94 GHz. The advantage of measuring the EPR spectra in the high-frequency range compared to the standard EPR technique is shown, which makes it possible to separate the EPR spectra characterized by different anisotropic
g
-factors and also to isolate the EPR signals due to the splitting of the fine structure for centers with high-spin states. In ceramics with a high content of magnetic Gd
3+
ions, EPR and electron spin echo (ESE) spectra of multi-ionic gadolinium complexes were observed, and EPR spectra of complexes with the maximum number of exchange-coupled gadolinium ions are seen at low temperatures. The temperature dependences of the EPR spectra indicates ferromagnetic ordering of exchange-coupled complexes of gadolinium.