Diffuse x-ray and inelastic neutron scattering study of the spin Peierl's transition in N-methyl-N-ethyl-morpholinium bistetracyanoquinodimethane (MEM-(TCNQ)/sub 2/)

Journal Article · Sat Aug 01 00:00:00 EDT 1981 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.24.1520· OSTI ID:6232334

Van Bodegom, B; Larson, B C; Mook, H A

X-ray and neutron scattering techniques have been used to investigate the spin Peierl's transition in N-methyl-N-ethyl-morpholinium bistetracyanoquinodimethane (MEM(TCNQ)/sub 2/). Both techniques reveal a doubling of the c-axis stacking of the TCNQ molecules below the transition. Diffuse x-ray scattering was observed well above the transition at the position of the low-temperature superlattice reflections. The geometry of the scattering showed that the critical scattering related to the structural changes at T/sub c/ results from fluctuations of a mainly transverse nature. Neutron scattering measurements revealed no softening of longitudinal-acoustic phonons at the transition. It was impossible to determine the position of the transverse-acoustic phonons, because they have either very low energies or very large linewidths; therefore, we cannot define the fluctuations to be of a static or dynamic character.

• Research Organization: Solid State Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 6232334
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Vol. 24:3
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
AMINES
CRYSTAL STRUCTURE
CRYSTAL-PHASE TRANSFORMATIONS
NEUTRON DIFFRACTION
X-RAY DIFFRACTION
HETEROCYCLIC COMPOUNDS
NITRILES
ETHERS
INELASTIC SCATTERING
PHONONS
SPIN
ANGULAR MOMENTUM
COHERENT SCATTERING
DIFFRACTION
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
PARTICLE PROPERTIES
PHASE TRANSFORMATIONS
QUASI PARTICLES
SCATTERING
360603* - Materials- Properties