Nature of hole doping in Nd[sub 2]NiO[sub 4] and La[sub 2]NiO[sub 4]: Comparison with La[sub 2]CuO[sub 4]

Journal Article · Sat May 01 00:00:00 EDT 1993 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.47.12365· OSTI ID:6891371

Tan, Z; Heald, S M ^[1]; Cheong, S; Cooper, A S ^[2]; Moodenbaugh, A R ^[1]

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1. Brookhaven National Laboratory, Upton, New York 11973 (United States)
2. AT T Bell Laboratories, Murray Hill, New Jersey 07974-2070 (United States)

To elucidate the hole doping mechanism, we have systematically studied the Ni and Cu [ital K]-edge x-ray-absorption spectra in doped Nd[sub 2]NiO[sub 4], La[sub 2]NiO[sub 4], and La[sub 2]CuO[sub 4]. We find a significant difference in the character of the doped hole between the nickelates and cuprate. We observe that both strontium substitution and introduction of excess oxygen lead to a shift of the Ni absorption edge to higher energies, by nearly 3 eV in NaSrNiO[sub 4]. This result demonstrates that the doped holes, in addition to the O 2[ital p] character, have a substantial amount of Ni 3[ital d] character (30--40 %). The intensity of the 1[ital s]-3[ital d] transition increases upon doping, consistent with increasing number of [ital d] holes. In contrast, the Cu absorption edge in the doped cuprate is shifted by much smaller amounts, indicative of a lower amount of Cu 3[ital d] character for the doped hole. The strongly mixed Ni 3[ital d] and O 2[ital p] character of the doped hole distinguishes the electronic structure of the nickelate from that of the cuprate.

• DOE Contract Number: AC02-76CH00016; AS05-80ER10742
• OSTI ID: 6891371
• Journal Information: Physical Review, B: Condensed Matter; (United States), Vol. 47:18; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COPPER OXIDES
CRYSTAL DOPING
LANTHANUM OXIDES
NEODYMIUM OXIDES
NICKEL OXIDES
HIGH-TC SUPERCONDUCTORS
HOLES
K SHELL
STRONTIUM
X-RAY SPECTRA
ALKALINE EARTH METALS
CHALCOGENIDES
COPPER COMPOUNDS
ELECTRONIC STRUCTURE
ELEMENTS
LANTHANUM COMPOUNDS
METALS
NEODYMIUM COMPOUNDS
NICKEL COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
RARE EARTH COMPOUNDS
SPECTRA
SUPERCONDUCTORS
TRANSITION ELEMENT COMPOUNDS
360207* - Ceramics
Cermets
& Refractories- Superconducting Properties- (1992-)