D.S. Jayalakshmi; M. Nasreen Banu; M. Sundareswari; D. Hemanand; E. Viswanathan
Abstract
The structural, bonding, magnetic, electronic, elastic and thermoelectric nature of superconducting material namely MgB2, with hexagonal structure (space group is 191) are studied by first principle calculation. The optimized lattice parameters of MgB2 are a=b=3.084289 Ǻ and c= 3.51527 Ǻ ...
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The structural, bonding, magnetic, electronic, elastic and thermoelectric nature of superconducting material namely MgB2, with hexagonal structure (space group is 191) are studied by first principle calculation. The optimized lattice parameters of MgB2 are a=b=3.084289 Ǻ and c= 3.51527 Ǻ and the electron phonon coupling constant (λ), Debye temperature, critical temperature, Seebeck coefficient, electrical resistivity and the elastic constants (C11, C12, C13, C33, C55) are calculated and agreed well with available outcome. To predict other possible superconducting materials belong to MgB2 family, Mg is further doped with transition element Titanium (Ti) and analyzed. Copyright © VBRI Press.
Madan Singh; Spirit Tlali; Krishna Chandra
Abstract
A simple theoretical model is developed to explore the size and shape dependence of thermal expansion and Debye temperature of nanomaterials. The model theory is based on cohesive energy and surface area change of the nanocrystals compared to the bulk crystals. It is found that the Debye temperature ...
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A simple theoretical model is developed to explore the size and shape dependence of thermal expansion and Debye temperature of nanomaterials. The model theory is based on cohesive energy and surface area change of the nanocrystals compared to the bulk crystals. It is found that the Debye temperature decreases with the decrease in particle size whereas, the thermal expansion increases as the particle size decreases. The present modelling results and predictions are very consistent with the available experiment results, implying that the model could be expected to be a general approach to understand the thermodynamic properties of nanomaterials. Copyright © 2017 VBRI Press
