An electron paramagnetic resonance study of Fe3+ centres in Tl2MgF4 and Tl2ZnF4 crystals

• Published in: Journal of physics. Condensed matter Vol. 18; no. 11; pp. 3053 - 3067
• Main Authors: Arakawa, M, Okamoto, A, Ebisu, H, Takeuchi, H
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 22.03.2006; Institute of Physics
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electron paramagnetic resonance and relaxation; Exact sciences and technology; Magnetic resonances and relaxations in condensed matter, mössbauer effect; Physics; Vacancies; Ternary compounds; Doping; Magnesium fluorides; Crystal symmetry; Thallium fluorides; Fine structure; Monocrystals; Spin Hamiltonians; Zinc fluorides; Anomaly; Iron additions; Electron paramagnetic resonance; Codoping; Lithium additions
• ISSN: 0953-8984; 1361-648X
• DOI: 10.1088/0953-8984/18/11/011

EPR measurements have been made on as-grown single crystals of Tl2MgF4 and Tl2ZnF4 doped only with Fe and co-doped with Fe and Li using an X-band spectrometer. Signals from the charge-uncompensated Fe3+ centre with tetragonal symmetry (centre I) were observed for both crystals. Signals from an Fe3+ centre with monoclinic symmetry (centre II) were also observed for Tl2ZnF4. On the basis of the spin-Hamiltonian separation analysis, centre II is ascribed to an Fe3+ ion substituting for a Zn2+ ion with a nearest Tl+ vacancy. The centre with orthorhombic symmetry (centre IV) observed in some Fe, Li co-doped Tl2ZnF4 crystals is ascribed to an Fe3+ ion associated with a Li+ ion at the nearest Zn2+ site. Anomalies were found in the fine structure parameters b20 for centres I and the separated parameters b2a(1) for centres II and IV, which have about double the magnitude of the corresponding values in Rb2ZnF4.