The coefficients of thermal expansion and the Gruneisen functions of trigonal and amorphous selenium in the temperature range between 10K and 300K

For trigonal selenium the coefficients of thermal expansion, alpha /sub ///, parallel to the chains, and alpha perpendicular to , perpendicular to the chains, have been calculated from dilatometric measurements in the temperature range 10K to 300K. By means of values of the specific heat cp(T) and the adiabatic elastic constants Cik(T) from literature the Gruneisen functions gamma in and gamma /sub /// have been computed in the quasiharmonic approximation. For vitreous selenium the coefficient of thermal expansion has been measured in the same temperature range. The Gruneisen function has been calculated from data of specific heat and the adiabatic bulk modulus Ks evaluated from ultrasound measurements. For comparing the thermomechanical behaviour of vitreous and trigonal selenium, respectively, the temperature dependent Gruneisen functions are discussed by means of a linear chain model.

[1]  R. Martin,et al.  Intermolecular bonding and lattice dynamics of Se and Te , 1976 .

[2]  R. Grosse,et al.  Lattice constants a and c of trigonal selenium between 85 and 380K , 1975 .

[3]  W. C. Hamilton,et al.  The phonon spectra of trigonal selenium at 77 and 298°K , 1974 .

[4]  A. B. Bestul,et al.  Heat capacities of selenium crystal (trigonal), glass, and liquid from 5 to 360 K , 1974 .

[5]  H. Böttger Vibrational Properties of Non‐Crystalline Solids , 1974 .

[6]  T. G. Gibbons Grüneisen functions of polymer polycrystals , 1974 .

[7]  M. Meissner,et al.  Specific Heat Measurements of Trigonal and Vitreous Selenium between 3 and 300 K by a Heat Pulse Method , 1973, June 16.

[8]  R W Munn,et al.  Role of the elastic constants in negative thermal expansion of axial solids , 1972 .

[9]  C. Guttman Low-Temperature Heat-Capacity Differences between Glasses and Their Crystals , 1972 .

[10]  H. Ibach,et al.  Thermal Expansion of Tellurium , 1970 .

[11]  R. K. Kirby,et al.  Thermal Expansion of Vitreous Selenium from—190° to +30°C , 1968 .

[12]  T. Barron,et al.  Analysis of the thermal expansion of anisotropic solids: Application to zinc , 1967 .

[13]  R. Roy,et al.  Elastic Constants of Selenium in the Hexagonal and Glassy Phases , 1966 .

[14]  R. Keezer,et al.  VAPOR‐LIQUID‐SOLID GROWTH OF SELENIUM CRYSTALS , 1966 .

[15]  W. Tiller,et al.  Growth of Large Single Crystals of Hexagonal Selenium from the Melt at High Pressures , 1965 .