Ioffe–Regel’ crossover and boson peaks in disordered solid solutions and similar anomalies in heterogeneous crystalline structures

Autor:	V. I. Grishaev, A. V. Kotlyar, S. B. Feodos’ev, E. S. Syrkin, Igor Gospodarev, E. V. Manzheliĭ, K. V. Kravchenko
Rok vydání:	2008
Předmět:	Physics Physics and Astronomy (miscellaneous) Condensed matter physics Crossover General Physics and Astronomy Condensed Matter::Disordered Systems and Neural Networks Heat capacity Acoustic dispersion symbols.namesake Lattice (order) symbols Density of states Debye model Solid solution Boson
Zdroj:	Low Temperature Physics. 34:655-664
ISSN:	1090-6517 1063-777X
Popis:	Low-frequency features of the phonon spectra of disordered solid solutions and heterogeneous crystalline structures are analyzed at the microscopic level. It is shown that boson-peak type excitations can arise in disordered solid solutions whose sites have only translational degrees of freedom. Thus it is established that such excitations appear mainly because of the additional positional dispersion of sound waves which is due to the disordering. The influence of boson-peak excitations on the low-temperature specific heat is investigated. It is found that in a number of cases the specific heat is more sensitive to excitations of this kind than the low-frequency density of states is. It is shown that anomalies similar to Ioffe–Regel’ crossover and boson peaks can also arise in disordered heterogeneous crystalline structures with a complicated lattice.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::da9b60b401d851f51df002395872cefc https://doi.org/10.1063/1.2967512 Zobrazit plný text záznamu