Valence determination as a function of doping in PrBa{sub 2}Cu{sub 3}O{sub 7}

Journal Article · Sat Jan 01 04:00:00 EST 2000 · Physical Review. B, Condensed Matter and Materials Physics

DOI:https://doi.org/10.1103/PhysRevB.61.1548· OSTI ID:20215100

Staub, U ^[1]; Soderholm, L ^[2]; Wasserman, S R ^[2]; Conner, A G. O. ^[3]; Kramer, M J ^[3]; Patterson, B D ^[1]; Shi, M ^[1]; Knapp, M ^[4]

---

1. Swiss Light Source, Paul Scherrer Institute, CH-5232 Villigen PSI, (Switzerland)
2. Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)
3. Ames Laboratory, U.S. Department of Energy, Iowa State University, Ames, Iowa 50011 (United States)
4. Material Sciences, Darmstadt University of Technology, D-64287 Darmstadt, (Germany)

We present results of x-ray absorption near edge spectra (XANES), neutron powder diffraction, and resonant x-ray diffraction on samples of PrBa{sub 2}Cu{sub 3}O{sub 7-{delta}} and Pr{sub 1-x}Ca{sub x}Ba{sub 2}Cu{sub 3}O{sub 7}. The data are obtained as a function of the doping levels of oxygen and Ca. There are significant changes in the Pr L{sub 3} XANES spectra with changes in oxygen or Ca concentrations, indicating that the Pr electronic properties are affected by doping. The resonant x-ray scattering experiments show that the changes observed occur on Pr ions incorporated in the PrBa{sub 2}Cu{sub 3}O{sub 7-{delta}} structure, and are not the result of changes to a Pr-containing impurity phase. A quantitative model, based on literature precedent, is used to extract Pr valences from the data, although the XANES cannot distinguish between models involving charge transfer and those involving hybridization. The results are compared with data obtained from Pb{sub 2}Sr{sub 2}Pr{sub 1-x}Ca{sub x}Cu{sub 3}O{sub 8}. The implications of these experiments are discussed in view of the exceptional magnetic and electronic properties of PrBa{sub 2}Cu{sub 3}O{sub 7-{delta}}. (c) 2000 The American Physical Society.

• OSTI ID: 20215100
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, Journal Name: Physical Review. B, Condensed Matter and Materials Physics Journal Issue: 2 Vol. 61; ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BARIUM OXIDES
CALCIUM OXIDES
COPPER OXIDES
CRYSTAL DOPING
ELECTRONIC STRUCTURE
EXPERIMENTAL DATA
HYBRIDIZATION
NEUTRON DIFFRACTION
PRASEODYMIUM OXIDES
STOICHIOMETRY
THEORETICAL DATA
VALENCE
X-RAY DIFFRACTION
X-RAY SPECTRA