ESR of Gd{sup 3+} and Er{sup 3+} in Pr{sub 2{minus}{ital x}}Ce{sub {ital x}}CuO{sub 4}

Journal Article · Mon May 01 04:00:00 EDT 1995 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.51.11909· OSTI ID:45925

Martins, G B; Rao, D; Valdivia, J A; Pires, M A; Barberis, G E; Rettori, C ^[1]; Venegas, P A ^[2]; Oseroff, S ^[3]; Fisk, Z ^[4]

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1. Instituto de Fisica ``Gleb Wataghin,`` Universidade Estadual de Campinas, 13083-970 Campinas, Sao Paulo (Brazil)
2. Departamento de Fisica, Universidade Estadual Paulista, 17033-360, Bauru, Sao Paulo (Brazil)
3. San Diego State University, San Diego, California 92182 (United States)
4. 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, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 17 Vol. 51; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
66 PHYSICS
CERIUM OXIDES
COPPER OXIDES
CRYSTAL FIELD
ELECTRON SPIN RESONANCE
ERBIUM IONS
GADOLINIUM IONS
MAGNETIC SUSCEPTIBILITY
MONOCRYSTALS
PRASEODYMIUM OXIDES