Neutron-spin-echo study of the reentrant spin glass Eu/sub x/Sr/sub 1-x/S

Journal Article · Mon Apr 15 04:00:00 EST 1985 · J. Appl. Phys.; (United States)

DOI:https://doi.org/10.1063/1.335034· OSTI ID:5770359

Shapiro, S M; Maletta, H; Mezei, F

Neutron-spin-echo (NSE) experiments were performed on polycrystalline samples of Eu/sub x/Sr/sub 1-x/S for x = 0.4 and 0.54 in the temperature range of 1.2 < T < 10 K and for 0.036 < Q < 0.18 A/sup -1/. The x = 0.4 sample exhibits a paramagnetic (PM) to spin-glass (SG) transition near T/sub g/ approx.2 K. In the x = 0.54 sample, large ferromagnetic correlations develop below 5 K and a SG state appears at lower temperatures. In the NSE experiment, the spin-spin correlation function S(Q,t) is measured directly for times between 0.03 < t < 5 nsec. At low temperatures, both materials exhibit a weak Q dependence in the dynamics and the spins are essentially frozen over the time range explored. On heating the x = 0.4 sample, the spins start to fluctuate more rapidly, but no dramatic change occurs around T/sub g/. On heating the x = 0.54 sample, S(Q,t) = decreases rapidly with time. Near 5 K, S(Q,t) is exponential (e/sup -Gammat/) with GAMMA being strongly Q dependent. Measurements of the depolarization of the scattered beam confirms the absence of true long-range ferromagnetic order below T/sub c/.

• Research Organization: Brookhaven National Laboratory, Upton, New York 11973
• DOE Contract Number: AC02-76CH00016
• OSTI ID: 5770359
• Journal Information: J. Appl. Phys.; (United States), Journal Name: J. Appl. Phys.; (United States) Vol. 57:8; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
ALKALINE EARTH METAL COMPOUNDS
CHALCOGENIDES
COHERENT SCATTERING
DEPOLARIZATION
DIFFRACTION
EUROPIUM COMPOUNDS
EUROPIUM SULFIDES
IMPURITIES
MAGNETISM
NEUTRON DIFFRACTION
PARAMAGNETISM
PHASE TRANSFORMATIONS
RARE EARTH COMPOUNDS
SCATTERING
SPIN ECHO
SPIN GLASS STATE
STRONTIUM COMPOUNDS
STRONTIUM SULFIDES
SULFIDES
SULFUR COMPOUNDS