Raman study of [ital R][sub 2[minus][ital x]]Ce[sub [ital x]]CuO[sub 4] ([ital R]=Pr,Nd,Sm): Resonance effects

Journal Article · Thu Oct 01 00:00:00 EDT 1992 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.46.8683· OSTI ID:6917248

Sanjuan, M L; Laguna, M A ^[1]; Pinol, S ^[2]; Canfield, P; Fisk, Z ^[3]

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1. ICMA, Universidad de Zaragoza enConsejo Superior de Investigaciones Cientificas, Facultad de Ciencias, 50009 Zaragoza (Spain)
2. ICMB Consejo Superior de Investigaciones Cientificas, Campus Universidad Autonoma de Barcelona, 08193 Bellaterra, Barcelona (Spain)
3. Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

We present resonant Raman scattering results of [ital T][prime]-phase cuprates [ital R][sub 2[minus][ital x]]Ce[sub [ital x]]CuO[sub 4] with [ital R]=Pr,Nd,Sm and [ital x] from 0 to 0.175. The two modes appearing in [ital zz] polarization show a different resonant behavior: whereas the allowed [ital A][sub 1[ital g]] is nonresonant in pure compounds and decreases towards the uv in doped ones, the forbidden mode [ital A][sup *] resonates towards uv in Nd and Sm samples with [ital x][ne]0, while for Pr compounds its evolution is similar to that of the [ital A][sub 1[ital g]]. We assign the [ital A][sup *] mode to a locally modified [ital A][sub 2[ital u]] mode, due to oxygen relaxation around Ce[sup 4+]. The resonance of this mode is interpreted in terms of electronic-band-structure calculations as involving transitions from O(1)[ital p][sub [ital z]]+O(2)[ital p][sub [ital z]] to empty cerium states, while the [ital A][sub 1[ital g]] decrease in the blue is attributed to light absorption due to the metallic character of doped samples.

• OSTI ID: 6917248
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 46:13; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
CERIUM COMPOUNDS
CERIUM OXIDES
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
ELECTRONIC STRUCTURE
HIGH-TC SUPERCONDUCTORS
INELASTIC SCATTERING
NEODYMIUM COMPOUNDS
NEODYMIUM OXIDES
OXIDES
OXYGEN COMPOUNDS
PRASEODYMIUM COMPOUNDS
PRASEODYMIUM OXIDES
RAMAN SPECTRA
RARE EARTH COMPOUNDS
RESONANCE SCATTERING
SAMARIUM COMPOUNDS
SAMARIUM OXIDES
SCATTERING
SPECTRA
SUPERCONDUCTORS
TEMPERATURE EFFECTS
TRANSITION ELEMENT COMPOUNDS