منابع مشابه
Phonon softening in Ni-Mn-Ga alloys
The TA2 phonon dispersion curves of Ni-Mn-Ga alloys with different compositions which transform to different martensitic structures have been measured over a broad temperature range covering both paramagnetic and ferromagnetic phases. The branches show an anomaly (dip) at a wave number that depends on the particular martensitic structure, and there is softening of these anomalous phonons with d...
متن کاملUnusual Phonon Softening in -Phase Plutonium
146401-1 The phonon density of states and adiabatic sound velocities were measured on fcc-stabilized Pu0:95Al0:05. The phonon frequencies and sound velocities decrease considerably (soften) with increasing temperature despite negligible thermal expansion. The frequency softening of the transverse branch along the [111] direction is anomalously large (~30%) and is very sensitive to alloy composi...
متن کاملPhonon dispersion in graphite.
We measured the dispersion of the graphite optical phonons in the in-plane Brillouin zone by inelastic x-ray scattering. The longitudinal and transverse optical branches cross along the Gamma-K as well as the Gamma-M direction. The dispersion of the optical phonons was, in general, stronger than expected from the literature. At the K point the transverse optical mode has a minimum and is only a...
متن کاملPhonon dispersion and electron-phonon coupling in MgB2 and AlB2.
We present a first principles investigation of the lattice dynamics and electron-phonon coupling of the superconductor MgB2 and the isostructural AlB2 within the framework of density functional perturbation theory using a mixed-basis pseudopotential method. Complete phonon dispersion curves and Eliashberg functions alpha2F are calculated for both systems. The main differences are related to hig...
متن کاملPhonon Softening and Superconductivity in Tellurium under Pressure.
The phonon dispersion and the electron-phonon interaction for the β-Po and the bcc high pressure phases of tellurium are computed with densityfunctional perturbation theory. Our calculations reproduce and explain the experimentally observed pressure dependence of the superconducting critical temperature (Tc) and confirm the connection between the jump in Tc and the structural phase transition. ...
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ژورنال
عنوان ژورنال: Physical Review B
سال: 2012
ISSN: 1098-0121,1550-235X
DOI: 10.1103/physrevb.86.220301