https://doi.org/10.1140/epjb/e2012-30799-0
Regular Article
Rare earth rhodium borides RRh3B (R = Y, Zr, and Nb): mechanical, thermal and optical properties
1 Department of Physics, Mawlana
Bhashani Science and Technology University, Santosh, Tangail - 1902, Bangladesh
2 Department of Physics, Rajshahi
University, 62005
Rajshahi,
Bangladesh
a e-mail: azi46@ru.ac.bd
Received:
3
September
2012
Received in final form:
30
September
2012
Published online:
3
December
2012
We report here ab initio density functional theory (DFT) calculations of structural, elastic, Peierls stress, thermodynamic and optical properties of RRh3B (R = Y, Zr and Nb) using the plane wave pseudopotential method. The materials possess better ductile behavior in comparison with a selection of layered MAX phases but the anisotropy is strong, particularly in NbRh3B. The Peierls stress, approximately 3-4 times larger than in MAX phases, show that dislocation movement may follow but with much reduced occurrences compared to MAX phases. The temperature and pressure dependence of bulk modulus, specific heats, thermal expansion coefficient, and Debye temperature are calculated for the first time for two of the three compounds using the quasi-harmonic Debye model with phononic effects for elevated temperature and pressure. The obtained results are discussed in comparison to the behavior of other related compounds. Further the features of optical functions obtained for the first time are discussed. The study reveals that the reflectivity is high in the IR-UV regions up to ~17.5 eV (YRh3B, ZrRh3B) and 20 eV (NbRh3B), thus showing promise as good coating materials.
Key words: Computational Methods
© EDP Sciences, Società Italiana di Fisica and Springer-Verlag, 2012