Atomistic simulation for structural and vibrational properties of R₂Co_7−xM_xB₃(R = Y, Gd; M = Ti, V, Cr)

Abstract

In order to study the effect of M substitution of transition elements on the structural properties of R2Co7−xMxB3 (R = Y, Gd; M = Ti, V, Cr) compounds, the phase stability and site preference are performed by using the pair potentials based on the lattice inversion technique. In R2Co7−xMxB3, M atoms substitute for Co with a strong preference for the 6i1 sites and the order of site preference is 6i1, 2c and 6i2. Calculated lattice parameters are in good agreement with the experimental data. Moreover, the total and partial phonon densities of states are first evaluated for the R2Co7B3 compounds with the hexagonal Ce2Co7B3-type structure.

Theoretical and Experimental Insights into the Effects of Zn Doping on the Magnetic and Magnetocaloric Properties of MnCoGe

“…Interestingly, the crystal structure refinement from neutron diffraction data showed only minor mixing between Mn and Co in the transition metal sites, with the Mn/Co ratio being 93:7 in the 2a site and 7:93 in the 2d site . This strong site preference seems counter-intuitive, given the similar metallic radii of Mn and Co, which typically substitute for each other readily in many intermetallic compounds. − We reasoned that the key to understanding the observed atomic distribution in h-MnCoGe lay in the electronic structure. Three models were used to simulate the switching of the Mn and Co atoms in the 2a and 2d sites (Figure ).…”

Arsenic-induced etched nanovoids on GaSb (100)

“…The threading dislocations seem to cluster at certain points in the image where the GaAs coalesces. 19 Figure 3͑c͒ shows a similar DF image of the GaAs coalescence over a truncated void. The truncated void in Fig.…”

Atomistic simulation of site preference, Curie temperature, and lattice vibration of Nd2Co7−xFex

“…Different from the above method, Chen's lattice inversion formula based on ab initio cohesive energy [18,19] is a rigorous and concise technique to obtain interatomic pair potentials, which can concisely and uniformly express the inversion coefficient of ma-terials with identical structures, making its analysis convenient. In our previous work, [15,20] the methods for obtaining the potentials have been reported in detail. The inverted pair potentials from the cohesive energy are approximately expressed as Morse function…”

“…[9−14] In the R m+n T 5m+3n B 2n series, the structural properties of the R 2 Co 7 B 3 series (for m = 1 and n = 3) with a Ce 2 Co 7 B 3 -type structure and the R 3 T 13 B 2 series (for m = 2, n = 1) with a Nd 3 Ni 13 B 2 -type struc-ture have been reported in our previous work. [15,16] Now, we extend our study to the case of R m+n T 2m+5n compounds. In the present paper, we investigate the m = 2, n = 2 system with hexagonal symmetry, Nd 2 Co 7−x Fe x .…”