6533b7dcfe1ef96bd12728ea
RESEARCH PRODUCT
Anomalous thermoelastic behavior of (KI)1-x(NH4I)x
R. FeileF. BruchhäuserC. BostoenS. HaussühlJean-françois Berretsubject
Condensed matter physicsPhononChemistrybusiness.industryGeneral ChemistryCondensed Matter PhysicsSymmetry (physics)IonThermoelastic dampingOpticsMean field theoryBrillouin scatteringQuadrupoleMaterials ChemistrybusinessSofteningdescription
Abstract An anomalous softening of the shear mode c 44 is observed in (KI) 1- x (NH 4 I) x with Brillouin scattering (10 K ⩽ T ⩽ 300 K ). It is caused by the weak quadrupolar moment of the NH 4 + ion, induced by the C 3 v symmetry of the potential. A parallel decrease of the lifetime of this transverse phonon at lower temperatures is observed. Static random strain fields due to admixing KI with NH 4 I are small. The results have been treated in terms of a mean field theory. The c 11 elastic constant does not show any anomalous behavior. Also are given the elastic constants c 11 and c 44 for x =0.14, 0.43 and 1 and 1 at T = 300 K and 10 K .
| year | journal | country | edition | language |
|---|---|---|---|---|
| 1990-06-01 | Solid State Communications |