Spin-Peierls and antiferromagnetic phases in Cu{sub 1{minus}x}Zn{sub x}GeO{sub 3}: A neutron-scattering study

Journal Article · Fri Aug 01 04:00:00 EDT 1997 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.56.3173· OSTI ID:528098

Martin, M C; Hase, M; Hirota, K; Shirane, G ^[1]; Sasago, Y; Koide, N; Uchinokura, K ^[2]

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1. Department of Physics, Brookhaven National Laboratory, Upton, New York 11973-5000 (United States)
2. Department of Applied Physics, University of Tokyo, Bunkyo-ku, Tokyo 113 (Japan)

Comprehensive neutron-scattering studies were carried out on a series of high-quality single crystals of Cu{sub 1{minus}x}Zn{sub x}GeO{sub 3}. The Zn concentration x was determined for each sample using electron probe microanalysis. The measured Zn concentrations were found to be 40{endash}80{percent} lower than the target values. Nevertheless, the measured concentrations cover a wide range which enables a systematic study of the effects due to Zn doping. We have confirmed the coexistence of spin-Peierls (SP) and antiferromagnetic (AF) orderings at low temperatures and the measured phase diagram is presented. Most surprisingly, long-range AF ordering occurs even in the lowest available Zn concentration x=0.42{percent}, which places important constraints on theoretical models of the AF-SP coexistence. Magnetic excitations are also examined in detail. The AF excitations are sharp at low energies and show no considerable broadening as x increases, indicating that the AF ordering remains long ranged for x up to 4.7{percent}. On the other hand, the SP phase exhibits increasing disorder as x increases, as shown from the broadening of the SP excitations as well as the dimer reflection peaks. {copyright} {ital 1997} {ital The American Physical Society}

• Research Organization: Brookhaven National Laboratory
• DOE Contract Number: AC02-76CH00016
• OSTI ID: 528098
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 6 Vol. 56; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANTIFERROMAGNETIC MATERIALS
ANTIFERROMAGNETISM
COPPER OXIDES
CRYSTAL DOPING
GERMANIUM OXIDES
MAGNETIC PROPERTIES
NEUTRON DIFFRACTION
PEIERLS METHOD
PHASE TRANSFORMATIONS
ZINC OXIDES