EPR study of the low-spin state of Ru³⁺in the YAl₃(BO₃)₄ and EuAl₃(BO₃)₄ aluminum borates

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• 作者：A.A. Prokhorov^a ; ^{andaprokhorov@gmail.com" class="auth_mail" title="E-mail the corresponding author} ; L.F. Chernush^b ; V.P. Dyakonov^c ; H. Szymczak^c ; A.D. Prokhorov^b
• 关键词：EPR spectra ; Rare-earth ; Aluminum borates ; Spin Hamiltonian parameters ; Superposition model ; Low-spin state
• 刊名：Journal of Magnetism and Magnetic Materials
• 出版年：2016
• 出版时间：15 December 2016
• 年：2016
• 卷：420
• 期：Complete
• 页码：285-289
• 全文大小：709 K

文摘

New data on the ground state of impurity Ru³⁺ ions in the crystals of YAl₃(BO₃)₄ and EuAl₃(BO₃)₄ aluminum borates were obtained. It was shown that Ru³⁺ ion replaces trivalent rare-earth ions without breaking the symmetry of the site. The crystal field acting on 4d⁵ ions forms an EPR spectrum, which is described by the spin Hamiltonian with S=1/2. The spin-Hamiltonian parameters determined are equal to g_II=1.963, g_⊥=3.796, A_II=43.03*10⁻⁴ cm⁻¹, A_⊥=84.86*10⁻⁴ cm⁻¹ in the YAl₃(BO₃)₄ crystal (at Т=15 K) and g_II=2.016, g_⊥=3.796 in the EuAl₃(BO₃)₄ crystal (at Т=15 K). It is found that the value of ∆g=g_II-g_⊥ is an indicator of distortions of nearest environment of Ru³⁺ ion. The angle between the C₃ axis and the direction into nearest oxygen ion was determined. The EPR linewidth of Ru³⁺ ion increases with increasing temperature due to the dipole-dipole and exchange interactions with the excited states of the host lattice Ru³⁺ ion.