Lattice dynamical theory of thermal expansion and mode Grüneisen parameters in cubic BP

Abstract

Lattice dynamical theory of thermal expansion and mode Grüneisen parameters in cubic boron monophosphide is reported in the quasiharmonic approximation within the framework of a second-neighbor rigid-ion model. In this scheme, we optimized the involved force constants by using nonlinear least-squares procedures with constrained parameters and weighting of the available data on critical-point phonons and elastic and lattice constants. Theoretical results of the phonon dispersion curves along high-symmetry directions ͑both at ambient and 89 kbar pressures͒, mode Grüneisen parameters, and thermal expansion coefficient ͕␣(T)͖ are compared and discussed with the existing experimental and ab initio calculations. Consistent with x-ray data, our calcualtion for the variation of ␣(T) with temperature in BP is found to be remarkably similar to that of ␤-SiC, and unlike most other III-V-compounds, it does not attain negative values at lower temperatures.

Optical and vibrational properties of Be-Zn chalcogenide alloys and superlattices

“…Earlier, we found similar atypical features in the phonon dispersions of B pnictides, III-Ns, and ␤ SiC. 62,63,69 We suspect such distinctiveness in the dynamical characteristics linked, most likely, to the lighter masses and radically different covalent radii of Be, B, N, and C, in Be chalcogenides, B pnictides, III-Ns, and IV-Cs, respectively. In the absence of acoustical ͑LA͒ phonons at the edge of the Brillouin zone our lattice dynamical calculations in Be chalcogenides fall well within the upper limits obtained 54 from the longest wave vectors and sound velocities ͕q m LA / ͑2c͖͒.…”

“…In this paper we have used a realistic lattice dynamical model [61][62][63][64] to undertake a comprehensive theoretical study ͑cf. Secs.…”

Studies on thermodynamic properties of III–V compounds by first‐principles response‐function calculation

“…Thermal expansion is a property in lattice dynamics. Theoretical investigations on the lattice dynamics of semiconductors have been accomplished by the bond-charge model [10][11][12][13], rigid-ion model [14,15], tight-binding model [16], frozen-phonon approximation [17,18], ab-initio molecular dynamics simulation [19], and mostly by density-functional perturbation theory calculations [20][21][22][23][24][25][26]. Considerable successes have been achieved in the theoretical evaluation on the thermal-expansion properties of many semiconductor materials [14, 16, 17, 19-21, 23, 26, 27].…”

Lattice dynamics and equilibrium properties of boron phosphide: a first-principles study

“…It is therefore not surprising that the electronic and structural properties of BP have been recalculated several times, and it is noticeable that, in the available theoretical investigations, 1 Author to whom correspondence should be addressed. some useful ground-state properties of BP such as elastic contants, bulk modulus, and band structure have been obtained with accuracy [8][9][10][11][12][13][14][15][16][17][18].…”

“…The theoretical works concerned with the lattice dynamical calculation for BP are also very limited in the public literature. Previous studies were either based on semi-empirical models [14], whose model parameters were fitted from experiments as well as ab initio calculations, or only provided phonon frequencies at critical points in the Brillouin zone (BZ) [12,13]. As for semi-empirical models, if only the input parameters were sufficient and well-examined, they generally run faster than the ab initio scheme and provide reliable calculated results.…”