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

Conference · Sun Jan 01 00:00:00 EST 1984

OSTI ID:6243518

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 < 10K and for 0.036 < Q < .18 A/sup -1/. The x = 0.4 sample exhibits a paramagnetic (PM) to spin glass (SG) transition near T/sub f/ approx. 2K. In the x = 0.54 sample, large ferromagnetic correlations develop below 5K and a spin-glass state appears at lower temperatures. In the NSE experiment, the spin-spin correlation function, S(Q,t), is measured directly for times between .03 < t < 5 ns. 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 f/. On heating the x = 0.54 sample, S (Q,t) decreases rapidly with time. Near the 5K, S(Q,t) is exponential (e/sup -GAMMA t/) 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 Lab., Upton, NY (USA); Kernforschungsanlage Juelich G.m.b.H. (Germany, F.R.). Inst. fuer Festkoerperforschung; Institut Max von Laue - Paul Langevin, 38 - Grenoble (France)
• DOE Contract Number: AC02-76CH00016
• OSTI ID: 6243518
• Report Number(s): BNL-35505; CONF-841184-29; ON: DE85004697
• Resource Relation: Conference: 30. annual conference on magnetism and magnetic materials, San Diego, CA, USA, 27 Nov 1984
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
EUROPIUM SULFIDES
PHASE TRANSFORMATIONS
STRONTIUM SULFIDES
NEUTRONS
SPIN ECHO
SPIN GLASS STATE
ULTRALOW TEMPERATURE
ALKALINE EARTH METAL COMPOUNDS
BARYONS
CHALCOGENIDES
ELEMENTARY PARTICLES
EUROPIUM COMPOUNDS
FERMIONS
HADRONS
NUCLEONS
RARE EARTH COMPOUNDS
STRONTIUM COMPOUNDS
SULFIDES
SULFUR COMPOUNDS
360603* - Materials- Properties