Spin glass freezing and superconductivity in YBa sub 2 (Cu sub 0. 94 Fe sub 0. 06 ) sub 3 O sub 7

Journal Article · Tue May 01 04:00:00 EDT 1990 · Journal of Applied Physics; (USA)

DOI:https://doi.org/10.1063/1.344856· OSTI ID:7122660

Mirebeau, I; Hennion, M ^[1]; Dianoux, J ^[2]; Caignaert, V ^[3]; Moorjani, K ^[4]

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1. Laboratoire Leon Brillouin (CEA-CNRS) CEN-Saclay 91191 Gif-sur-Yvette Cedex, France (FR)
2. Ill 156X Centre de Tri, 38042 Grenoble Cedex (France)
3. Laboratoire CRISMAT I.S.M., Universite de Caen, 14032 Caen (France)
4. Applied Physics Laboratory, The John Hopkins University, Laurel, Maryland 20707 (USA)

We have studied the dynamics of the iron spins in a superconducting YBa{sub 2}(Cu{sub 0.94}Fe{sub 0.06}){sub 3}O{sub 7} sample by neutron time-of-flight measurements. The range of scattering vector {ital q} was 0.1{lt}{ital q}{lt}2.1 A{sup {minus}1}, and the energy resolution 80 {mu}eV. The temperature was varied in the range 1.8 K{lt}{ital T}{lt}300 K. In the whole temperature range, the {ital q} dependence of the magnetic intensity mainly reflects the magnetic form factor of iron which shows that the iron spins are almost uncorrelated. The elastic and quasielastic intensities strongly vary with temperature. A spin-glass-like freezing is revealed at low temperature by a sharp decrease of the quasielastic intensity, an increase of the elastic, or resolution limited intensity and a minimum in the quasielastic width. The freezing temperature ({ital T}{sub {ital f}}{congruent}18 K) corresponds to that already determined by a magnetic splitting in Moessbauer experiments. Above {ital T}{sub {ital f}}, the relaxation of the iron spins in the paramagnetic state is modified by the occurrence of superconductivity. We observe a slight increase of the quasielastic intensity and of the quasielastic width at the superconducting transition ({ital T}{sub {ital c}}{congruent}74 K), possibly related to the electron-spin coupling.

• OSTI ID: 7122660
• Journal Information: Journal of Applied Physics; (USA), Journal Name: Journal of Applied Physics; (USA) Vol. 67:9; ISSN 0021-8979; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
BARIUM OXIDES
CHALCOGENIDES
COHERENT SCATTERING
COPPER COMPOUNDS
COPPER OXIDES
DIFFRACTION
IRON COMPOUNDS
IRON OXIDES
LOW TEMPERATURE
MEDIUM TEMPERATURE
NEUTRON DIFFRACTION
OXIDES
OXYGEN COMPOUNDS
SCATTERING
SPIN GLASS STATE
SUPERCONDUCTORS
TIME-OF-FLIGHT METHOD
TRANSITION ELEMENT COMPOUNDS
ULTRALOW TEMPERATURE
VERY LOW TEMPERATURE
YTTRIUM COMPOUNDS
YTTRIUM OXIDES