Lattice dynamics of commensurate and incommensurate K/sub 2/SeO/sub 4/

Journal Article · Wed Oct 01 04:00:00 EDT 1980 · Phys. Rev., B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.22.3408· OSTI ID:5131573

Axe, J D; Iizumi, M; Shirane, G

K/sub 2/SeO/sub 4/ undergoes an incommensurate structural transformation at T/sub 0/=128 K followed by a commensurate ''lock-in'' transformation at T/sub c/=93 K. Below T/sub 0/, the soft-phonon mode associated with the transformation is ''split'' into modes representing fluctuations in amplitude and phase of the complex order parameter. We have studied the dispersion and temperature dependence of these modes at T < or = 118 K. We have also seen intensity anomalies which can be explained by interactions between a transverse-acoustic-phonon branch and the low-lying ''phason'' branch.

• Research Organization: Brookhaven National Laboratory, Upton, New York 11973
• OSTI ID: 5131573
• Journal Information: Phys. Rev., B: Condens. Matter; (United States), Journal Name: Phys. Rev., B: Condens. Matter; (United States) Vol. 22:7; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360602* -- Other Materials-- Structure &amp; Phase Studies
ALKALI METAL COMPOUNDS
ALLOYS
AMPLITUDES
COHERENT SCATTERING
DIFFRACTION
DISPERSION RELATIONS
FLUCTUATIONS
NEUTRON DIFFRACTION
OSCILLATION MODES
OXYGEN COMPOUNDS
PHASE STABILITY
PHASE TRANSFORMATIONS
PHONONS
POTASSIUM COMPOUNDS
QUASI PARTICLES
SCATTERING
SELENATES
SELENIUM COMPOUNDS
STABILITY
TEMPERATURE DEPENDENCE
TRANSITION AMPLITUDES
VARIATIONS