ESR of Gd{sup 3+} and Er{sup 3+} in Pr{sub 2{minus}{ital x}}Ce{sub {ital x}}CuO{sub 4}
- Instituto de Fisica ``Gleb Wataghin,`` Universidade Estadual de Campinas, 13083-970 Campinas, Sao Paulo (Brazil)
- Departamento de Fisica, Universidade Estadual Paulista, 17033-360, Bauru, Sao Paulo (Brazil)
- San Diego State University, San Diego, California 92182 (United States)
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
Electron spin resonance (ESR) of Gd{sup 3+} and Er{sup 3+} in single crystals of Pr{sub 2{minus}{ital x}}Ce{sub {ital x}}CuO{sub 4} (0{le}{ital x}{le}0.15) at liquid-helium temperature shows crystal field (CF) effects corresponding to a {ital C}{sub 4{ital v}} point symmetry. Upon doping with Ce{sup 4+}, a reduction of about 23% in the second-order CF parameter {vert_bar}{ital b}{sub 20}{vert_bar} is found with no significant change for the other CF spin-Hamiltonian parameters. The resonance lines broaden and present a Dysonian line shape at higher Ce{sup 4+} concentration, which is consistent with an increase in the CF inhomogeneity and the metallic character of the compound. Magnetic-susceptibility measurements present a small increase in the low-temperature anisotropy upon doping, consistent with a smaller {l_angle}{vert_bar}{ital B}{sub 0}{sup 2}{vert_bar}{r_angle} crystal-field parameter for Pr{sup 3+} in Pr{sub 2{minus}{ital x}}Ce{sub {ital x}}CuO{sub 4}. The reduction in the CF parameters is tentatively attributed to charge transfer from Ce atoms to the CuO{sub 2} planes. The exchange parameters {ital j}{sub Gd-Pr} and {ital j}{sub Pr-Pr} are estimated from the ESR and susceptibility measurements.
- OSTI ID:
- 45925
- Journal Information:
- Physical Review, B: Condensed Matter, Vol. 51, Issue 17; Other Information: PBD: 1 May 1995
- Country of Publication:
- United States
- Language:
- English
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