LOW TEMPERATURE SPECIFIC HEAT OF INTERMETALLICS (Ti/Be)B2

2007 ◽  
Vol 21 (14) ◽  
pp. 885-891 ◽  
Author(s):  
NUPINDER KAUR ◽  
N. K. GAUR ◽  
R. K. SINGH
Keyword(s):  
Experimental Data ◽  
Thermal Properties ◽  
Low Temperature ◽  
Specific Heat ◽  
Debye Temperature ◽  
Cohesive Energy ◽  
Specific Heats ◽  
Molecular Force ◽  
Low Temperature Specific Heat ◽  
Rigid Ion Model

We have applied the Rigid Ion Model (RIM) to study the cohesive and thermal properties of binary intermetallic BeB 2 and TiB 2. The paper reports the calculated results on cohesive energy (ϕ), compressibility (β), molecular force constant (f), Restrahalen frequency (ν0), Debye temperature (Θ D ) and Gruneisen parameter (γ) for the temperature range 50 K ≤ T ≤ 300 K and the effect of van der Waal interaction on these properties are also shown. Our results on Debye temperature are closer to the experimental data. In addition, we have computed the specific heats for BeB 2 and TiB 2 and compared them with the available experimental data.

ELASTIC AND THERMAL PROPERTIES OF Sr1-xCaxRuO3

2013 ◽  
Vol 27 (17) ◽  
pp. 1350054 ◽  
Author(s):  
RASNA THAKUR ◽  
RAJESH K. THAKUR ◽  
N. K. GAUR
Keyword(s):  
Experimental Data ◽  
Thermal Expansion ◽  
Thermal Properties ◽  
Specific Heat ◽  
Debye Temperature ◽  
Cohesive Energy ◽  
Molecular Force ◽  
Almost All ◽  
Good Agreement ◽  
Rigid Ion Model

We have investigated the elastic and thermal properties of Sr 1-x Ca x RuO 3(0≤x ≤1) perovskite using a modified rigid ion model (MRIM). The trend of variation of our computed specific heat in the temperature range 1 K ≤ T ≤ 1000 K are in good agreement with corresponding experimental data for almost all the compositions (x). The specific heat found to increase with temperature from 1 K to 300 K, while they decrease with concentration (x) for these perovskite ruthenates. Besides, we have reported the thermal properties, like thermal expansion (α), molecular force constant (f), Reststrahlen frequency (υ), cohesive energy (ϕ), Debye temperature (θD) and Gruneisen parameter (γ).

Elastic and Thermal Properties of SrCo1-xScxO3-δ

2014 ◽  
Vol 975 ◽  
pp. 283-287
Author(s):  
Rasna Thakur ◽  
Rajesh K. Thakur ◽  
N.K. Gaur
Keyword(s):  
Thermal Properties ◽  
Specific Heat ◽  
Debye Temperature ◽  
Elastic Constants ◽  
Cohesive Energy ◽  
Second Order ◽  
Grüneisen Parameter ◽  
Gruneisen Parameter ◽  
Rigid Ion Model

We have investigated the elastic and thermal properties for perovskite SrCo1-xScxO3-d, by means of Modified Rigid Ion Model (MRIM). We have also computed the second order Elastic constants (SOECs) and their combinations. Besides we have reported the cohesive energy (f), Debye temperature (θD) and Gruneisen parameter (γ). The variation of specific heat (C) at temperature 15 K≤x≤1000 K is computed for SrCo1-xScxO3-d. The computed properties reproduce well with the available data in literature.

scholarly journals Thermodynamic Properties of La1-xSmxCoO3

2014 ◽  
Vol 2014 ◽  
pp. 1-5
Author(s):  
Rasna Thakur ◽  
N. K. Gaur
Keyword(s):  
Experimental Data ◽  
Thermal Expansion ◽  
Thermal Properties ◽  
Bulk Modulus ◽  
Specific Heat ◽  
Specific Heats ◽  
Lattice Specific Heat ◽  
Lattice Distortions ◽  
First Time ◽  
Rigid Ion Model

We have investigated the bulk modulus and thermal properties of La1-xSmxCoO3 (0≤x≤0.2) at temperatures 1 K≤T≤300 K probably for the first time by incorporating the effect of lattice distortions using the modified rigid ion model (MRIM). The calculated specific heat, thermal expansion, bulk modulus, and other thermal properties reproduce well with the available experimental data, implying that MRIM represents properly the nature of the pure and doped cobaltate. The specific heats are found to increase with temperature and decrease with concentration (x) for the present. The increase in Debye temperature (θD) indicates an anomalous softening of the lattice specific heat because increase in T3-term in the specific heat occurs with the decrease of concentration (x).

SPECIFIC HEAT OF Tb0.5Sr0.5CoO3 CERAMICS

2013 ◽  
Vol 22 ◽  
pp. 391-396
Author(s):  
RASNA THAKUR ◽  
RAJESH K. THAKUR ◽  
N. K. GAUR
Keyword(s):  
Experimental Data ◽  
Thermodynamic Properties ◽  
Bulk Modulus ◽  
Specific Heat ◽  
Debye Temperature ◽  
Cohesive Energy ◽  
Grüneisen Parameter ◽  
Temperature Range ◽  
Proper Interpretation ◽  
Rigid Ion Model

We have investigated the thermal and allied properties of Tb0.5Sr0.5CoO3 for the temperature range 1K≤T≤300K using the Modified Rigid Ion Model (MRIM). The calculated bulk modulus, specific heat, and other thermodynamic properties obtained from MRIM have presented proper interpretation of the experimental data, for Sr ions doped TbCoO3 . In addition, the results on the cohesive energy (φ), Debye temperature (θD) and Gruneisen parameter (γ) are also discussed.

LOW TEMPERATURE SPECIFIC HEAT OF (KBr)1-x(KCN)x MIXED CRYSTAL

2003 ◽  
Vol 17 (26) ◽  
pp. 1391-1398 ◽  
Author(s):  
N. K. GAUR ◽  
NUPINDER KAUR ◽  
MANIK MANAKE ◽  
JYOTSNA GALGALE ◽  
R. K. SINGH
Keyword(s):  
Experimental Data ◽  
Thermal Properties ◽  
Specific Heat ◽  
Mixed Crystal ◽  
Body Force ◽  
Molecular Force ◽  
Low Temperature Specific Heat ◽  
Three Body ◽  
First Time ◽  
Good Agreement

We have investigated the cohesive and thermodynamic properties of ( KBr )1-x( KCN )x using an extended three-body force shell model (ETSM), which has been found to be adequately suitable for the description of orientationally disordered mixed cyanide-halide crystals. The specific heat of ( KBr )1-x( KCN )x for compositions (x=0.53, 0.65, 0.73, 0.84 and 0.93) at temperature 10 K ≤T≤150 K have been computed using the ETSM for the first time. The paper also reports the calculated results on Debye temperature (Θ D ), cohesive energy (Φ), compressibility (β), molecular force constant (f) and Restrahlen frequency (ν0) of ( KBr )1-x( KCN )x. The results on specific heat and some other thermal properties are in good agreement with their available experimental data.

PHONON DEPENDENCE ON THERMAL PROPERTIES OF RGaO3(R = La, Ce, Nd, Pr, Sm, Gd)

2012 ◽  
Vol 01 (01) ◽  
pp. 1250006
Author(s):  
ATAHAR PARVEEN ◽  
N. K. GAUR
Keyword(s):  
Experimental Data ◽  
Thermal Properties ◽  
Rare Earth ◽  
Bulk Modulus ◽  
Specific Heat ◽  
Temperature Dependence ◽  
Debye Temperature ◽  
Van Der Waals Interactions ◽  
Cohesive Properties ◽  
Rigid Ion Model

We have systematically investigated the effect of phonons on elastic, thermal and cohesive properties for rare earth gallates RGaO3 (R = La, Ce, Nd, Pr, Sm, Gd) by means of a Rigid Ion Model after modifying its framework to incorporate the van der Waals interactions. Besides that, we have calculated the temperature dependence of the specific heat for the present orthogallates. The results on bulk modulus, Debye temperature and specific heat reproduce well with the available experimental data.

THE ELASTIC AND THERMODYNAMIC PROPERTIES OF Lu DOPED ScVO3

2012 ◽  
Vol 26 (31) ◽  
pp. 1250190
Author(s):  
ATAHAR PARVEEN ◽  
N. K. GAUR
Keyword(s):  
Experimental Data ◽  
Thermal Properties ◽  
Phase Transitions ◽  
Thermodynamic Properties ◽  
Specific Heat ◽  
Structural Phase ◽  
Magnetic Ordering ◽  
Structural Phase Transitions ◽  
Lattice Distortions ◽  
Rigid Ion Model

We have investigated the elastic, cohesive and thermal properties of (Lu, Sc) VO 3 and Sc 1-x Lu x VO 3(0.6 ≤ x ≤ 0.9) perovskites by means of a modified rigid ion model (MRIM). The variation of specific heat is determined following the temperature driven structural phase transitions. Also, the effect of lattice distortions on the elastic and thermal properties of the present pure and doped vanadates has been studied by an atomistic approach. The calculated bulk modulus (BT), reststrahlen frequency (ν0), cohesive energy (ϕ), Debye temperature (θD) and Gruneisen parameter (γ) reproduce well with the corresponding experimental data. The specific heat results can further be improved by including the magnetic ordering contributions to the specific heat.

Order?Disorder Transformations in Alloys. The Inclusion of Non-nearest Neighbour Interactions in Cluster Variation Methods. II. Low Temperature Specific Heats for Body Centred Cubic Lattices

1981 ◽  
Vol 34 (1) ◽  
pp. 75 ◽  
Author(s):  
Joan M Hanley ◽  
Thomas E Peacock
Keyword(s):  
Critical Temperature ◽  
Low Temperature ◽  
Specific Heat ◽  
Interaction Energy ◽  
Cluster Variation Method ◽  
Variation Method ◽  
Nearest Neighbour ◽  
Specific Heats ◽  
Low Temperature Specific Heat ◽  
Cluster Variation

In Part I, the Sanchez and de Fontaine formulation of the cluster variation method was used to study the dependence of the critical temperature and the high temperature specific heat on the ratio of second neighbour to nearest neighbour interaction energy. This method can be extended to find solutions for the ordered state. The dependence of the low temperature specific heat on the interaction energy ratio is studied. As with the critical temperature and high T specific heat studies, it is found that both the sign and magnitude of ex affect the low temperature specific heat.

Low temperature specific heats of zinc alloyed with silver

1975 ◽  
Vol 343 (1634) ◽  
pp. 363-374 ◽  
Keyword(s):  
Low Temperature ◽  
Fermi Level ◽  
Specific Heat ◽  
Debye Temperature ◽  
Density Of States ◽  
Electronic Specific Heat ◽  
Pure Zinc ◽  
Specific Heats ◽  
Complete Breakdown ◽  
Specific Heat Coefficient

Measurements of the electronic specific heat coefficient and of the limiting Debye temperature are reported for pure zinc and for two n-phase alloys containing 2 at. % and 4 at. % silver in zinc, respectively. After a correction for electron-phonon enhancement the electronic specific heat coefficient for pure zinc differs by only a small percentage from the calculated value reported in the literature on the basis of a band calculation. The results for the alloys show a decreasing trend of the density of states at the Fermi level when silver is added to zinc. This is contrary to a prediction based on a rigid band approach. Hence, the results indicate a complete breakdown of the rigid band condition on alloying. The reasons for this are most likely associated with the influence of the d band electrons or with charge distribution effects between solute and solvent atoms.

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