Spin dynamics in CuO and Cu[sub 1[minus][ital x]]Li[sub [ital x]]O from [sup 63]Cu and [sup 7]Li nuclear relaxation

Journal Article · Sun Aug 01 04:00:00 EDT 1993 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.48.3433· OSTI ID:5429879

Carretta, P; Corti, M; Rigamonti, A ^[1]

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1. Department of Physics Alessandro Volta,'' University of Pavia, Via Bassi 6, 27100 Pavia (Italy)

[sup 63]Cu nuclear quadrupole resonance (NQR), nuclear antiferromagnetic resonance (AFNMR), and spin-lattice relaxation, as well as [sup 7]Li NMR and relaxation measurements in CuO and in Cu[sub 1[minus][ital x]]Li[sub [ital x]]O, are used to study the spin dynamics in the paramagnetic and in the antiferromagnetic (AF) phase, and in particular the effects induced by lithium doping. It is argued that Li enters in CuO lattice up to a doping [ital x] around 4%; from a comparison of the electric-field gradient (EFG) and of the dipolar field at the nucleus with theoretical estimates, it appears that Li[sup +] is slightly displaced from the Cu lattice site. From NQR, NMR, and AFNMR spectra, information on the Cu hyperfine interaction and the EFG are derived. The Neel temperature [ital T][sub [ital N]] is affected by Li doping to a moderate extent, decreasing from 226 K in CuO to [ital T][sub [ital N]]=183 K for [ital x]=3.7%. The relaxation rates, driven by the time-dependent part of the magnetic electron-nucleus Hamiltonians, indicate that the Cu[sup 2+] spin dynamics is almost unaffected by Li doping for [ital T][much gt][ital T][sub [ital N]] and possibly controlled by valence fluctuations. The Li doping modifies in a dramatic way the spin fluctuations in the AF phase.

• OSTI ID: 5429879
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 48:5; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360207* -- Ceramics
Cermets
& Refractories-- Superconducting Properties-- (1992-)
ALKALI METAL COMPOUNDS
CHALCOGENIDES
COPPER 63
COPPER COMPOUNDS
COPPER ISOTOPES
COPPER OXIDES
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
HIGH-TC SUPERCONDUCTORS
HOLES
INTERMEDIATE MASS NUCLEI
ISOTOPES
LITHIUM COMPOUNDS
LITHIUM OXIDES
MAGNETIC MATERIALS
MAGNETIC PROPERTIES
MAGNETISM
MATERIALS
NEEL TEMPERATURE
NUCLEAR QUADRUPOLE RESONANCE
NUCLEI
ODD-EVEN NUCLEI
OXIDES
OXYGEN COMPOUNDS
PARAMAGNETISM
PHYSICAL PROPERTIES
RELAXATION
RESONANCE
SEMICONDUCTOR MATERIALS
SPIN-LATTICE RELAXATION
STABLE ISOTOPES
STOICHIOMETRY
SUPERCONDUCTIVITY
SUPERCONDUCTORS
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE
TEMPERATURE RANGE 0065-0273 K
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TRANSITION TEMPERATURE
VALENCE