Magnetic excitations in pure, lightly doped, and weakly metallic La[sub 2]CuO[sub 4]

Journal Article · Tue Dec 01 04:00:00 EST 1992 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.46.14034· OSTI ID:7166209

Keimer, B; Belk, N; Birgeneau, R J; Cassanho, A; Chen, C Y; Greven, M; Kastner, M A ^[1]; Aharony, A ^[2]; Endoh, Y ^[3]; Erwin, R W ^[4]; Shirane, G ^[5]

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1. Center for Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)
2. School of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978 (Israel)
3. Department of Physics, Tohoku University, Sendai 980 (Japan)
4. National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States)
5. Brookhaven National Laboratory, Upton, New York 11973 (United States)

We report a comprehensive neutron-scattering study of the evolution of the magnetic excitations in La[sub 2[minus][ital x]]Sr[sub [ital x]]CuO[sub 4] for 0[le][ital x][le]0.04. We first present accurate measurements of the magnetic correlation length and the sublattice magnetization of a carrier-free La[sub 2]CuO[sub 4] crystal and analyze these in the context of recent theoretical predictions. We then systematically investigate the influence of different dopants on the magnetism: Our measurements indicate that static vacancies in the La[sub 2]Cu[sub 1[minus][ital y]]Zn[sub [ital y]]O[sub 4] system affect the magnetic correlations in a similar manner as electrons in Pr[sub 2[minus][ital x]]Ce[sub [ital x]]CuO[sub 4]. The magnetic correlation length is much more rapidly suppressed as a function of [ital x] in La[sub 2[minus][ital x]]Sr[sub [ital x]]CuO[sub 4], and for [ital x][le]0.04 we find that it obeys the empirical relation [xi][sup [minus]1]([ital x],[ital T])=[xi][sup [minus]1]([ital x],0)+[xi][sup [minus]1](0,[ital T]), where [xi](0,[ital T]) is the measured correlation length of the carrier-free sample. We also report an extensive set of measurements of the dynamical magnetic response function of a crystal of composition La[sub 1.96]Sr[sub 0.04]CuO[sub 4] for excitation energies 0.75[le][omega][le]45 meV and temperatures 1.5[le][ital T][le]500 K.

• DOE Contract Number: AC02-76CH00016
• OSTI ID: 7166209
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 46:21; ISSN 0163-1829; ISSN PRBMDO
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360107* -- Metals & Alloys-- Superconducting Properties-- (1992-)
ALLOYS
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
DIAGRAMS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
FUNCTIONS
LANTHANUM COMPOUNDS
LANTHANUM OXIDES
MAGNETIZATION
OXIDES
OXYGEN COMPOUNDS
PHASE DIAGRAMS
PHYSICAL PROPERTIES
RARE EARTH COMPOUNDS
RESPONSE FUNCTIONS
STRONTIUM ADDITIONS
STRONTIUM ALLOYS
SUPERCONDUCTORS
TRANSITION ELEMENT COMPOUNDS