SIZE AND TEMPERATURE EFFECT ON THERMAL EXPANSION COEFFICIENT AND LATTICE PARAMETER OF NANOMATERIALS

2013 ◽  
Vol 27 (25) ◽  
pp. 1350180 ◽  
Author(s):  
RAGHUVESH KUMAR ◽  
GEETA SHARMA ◽  
MUNISH KUMAR
Keyword(s):  
Experimental Data ◽  
Thermal Expansion ◽  
Temperature Dependence ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Size Dependence ◽  
Coefficient Of Thermal Expansion ◽  
Lattice Parameter ◽  
Model Predictions ◽  
Good Agreement

A simple theoretical model is developed to study the effect of size and temperature on the coefficient of thermal expansion and lattice parameter of nanomaterials. We have studied the size dependence of thermal expansion coefficient of Pb , Ag and Zn in different shape viz. spherical, nanowire and nanofilm. A good agreement between theory and available experimental data confirmed the model predictions. We have used these results to study the temperature dependence of lattice parameter for different size and also included the results of bulk materials. The temperature dependence of lattice parameter of Zn nanowire and Ag nanowire are found to present a good agreement with the experimental data. We have also computed the temperature and size dependence of lattice parameter of Se and Pb for different shape viz. spherical, nanowire and nanofilm. The results are discussed in the light of recent research on nanomaterials.

Equation of state and thermal expansion of metals with FCC structure: Application to Cu, Al and Ni

2014 ◽  
Vol 28 (26) ◽  
pp. 1450209
Author(s):  
Pham Dinh Tam ◽  
Nguyen Quang Hoc ◽  
Bui Duc Tinh ◽  
Nguyen Duc Hien
Keyword(s):  
Thermal Expansion ◽  
Equation Of State ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Analytic Form ◽  
Lattice Parameter ◽  
Different Temperatures ◽  
Simple Analytic Form ◽  
Fcc Structure ◽  
Good Agreement

The equation of state, the expressions of lattice parameter and thermal expansion coefficient in general form are obtained by the statistical moment method. Applying to Cu , Al and Ni metals, we determine these properties in simple analytic form for each metal. Numerical results for the thermal expansion coefficient of these metals in different temperatures and pressures are in good agreement with experiments.

scholarly journals BARIC DEPENDENCE OF LATTICE PROPERTIES FOR DIAMOND

2018 ◽  
Vol 59 (9) ◽  
pp. 57
Author(s):  
Makhach N. Magomedov
Keyword(s):  
Experimental Data ◽  
Thermal Expansion ◽  
Elastic Modulus ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Interatomic Potential ◽  
State Equation ◽  
Relative Volume ◽  
Lennard Jones ◽  
Good Agreement

Based on the pairwise interatomic potential of Mi-Lennard-Jones and the Einstein's model of crystal the state equation P(V/V0, T) and the baric dependencies of the lattice properties for diamond were obtained. The calculations were performed along two isotherms: T = 300 and 3000 K and until to P = 10000 kbar (i.e. until to the relative volume V/V0 = 0.5). The baric dependencies for the following properties were obtained: isothermal elastic modulus, isochoric and isobaric heat capacities and thermal expansion coefficient. Good agreement with experimental data was obtained.

Reduction in Wear Rate of α-Alumina and Silicon Nitride by Diffusional Surface Modification

1988 ◽  
Vol 140 ◽  
Author(s):  
A.K. Gangopadhyay ◽  
M.E. Fine ◽  
H.S. Cheng
Keyword(s):  
Wear Resistance ◽  
Thermal Expansion ◽  
Surface Modification ◽  
Silicon Nitride ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Surface Region ◽  
Lattice Parameter ◽  
Lower Thermal Expansion ◽  
Wear Modes

AbstractThe surface regions of α-alumina and hot pressed silicon nitride were modified by suitable alloying in order to improve their wear resistance. The surface modification in polycrystalline α-alumina was done by diffusing chromia into the surface region which resulted in the formation of a thin layer of A12O3 - Cr9O3 solid solution which has a lower thermal expansion coefficient than pure α-alumina. Also Cr2O3 has a larger lattice parameter than α-alumina thus during cooling the surface was put into compression. The surface region of hot pressed silicon nitride was modified by diffusing α-alumina into the surface which resulted in the formation of a thin sialon layer. A surface compressive stress was again introduced due to the lower thermal expansion coefficient and larger latticeparameter of sialon compared to silicon nitride.Wear tests were conducted against 52100 steel under both lubricated and unlubricated sliding contact using a block on ring apparatus. The wear resistance of chromia surface alloyed α-alumina was improved considerably over unalloyed α-alumina under both lubricated and unlubricated conditions. The wear resistance of alumina surface alloyed silicon nitride was also improved over unalloyed silicon nitride under both lubricated and unlubricated conditions.Different wear modes were identified by examining the worn surfaces under the scanning electron microscope.

Single-crystal Fe-bearing sphalerite: synthesis, lattice parameter, thermal expansion coefficient and microhardness

2016 ◽  
Vol 44 (4) ◽  
pp. 287-296 ◽  
Author(s):  
Dmitriy A. Chareev ◽  
Valentin O. Osadchii ◽  
Andrey A. Shiryaev ◽  
Alexey N. Nekrasov ◽  
Anatolii V. Koshelev ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Single Crystal ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Lattice Parameter

ANHARMONIC EFFECTIVE POTENTIAL, LOCAL FORCE CONSTANT AND EXAFS OF HCP CRYSTALS: THEORY AND COMPARISON TO EXPERIMENT

2008 ◽  
Vol 22 (29) ◽  
pp. 5155-5166 ◽  
Author(s):  
NGUYEN VAN HUNG ◽  
TONG SY TIEN ◽  
LE HAI HUNG ◽  
RONALD R. FRAHM
Keyword(s):  
Thermal Expansion ◽  
Fine Structure ◽  
Thermal Expansion Coefficient ◽  
Force Constant ◽  
Expansion Coefficient ◽  
Effective Potential ◽  
X Ray ◽  
X Ray Absorption ◽  
Analytical Expressions ◽  
Good Agreement

Anharmonic effective potential, Extended X-ray Absorption Fine Structure (EXAFS) and its parameters of hcp crystals have been theoretically and experimentally studied. Analytical expressions for the anharmonic effective potential, effective local force constant, three first cumulants, a novel anharmonic factor, thermal expansion coefficient and anhamonic contributions to EXAFS amplitude and phase have been derived. This anharmonic theory is applied to analyze the EXAFS of Zn and Cd at 77 K and 300 K, measured at HASYLAB (DESY, Germany). Numerical results are found to be in good agreement with experiment, where unnegligible anharmonic effects have been shown in the considered theoretical and experimental quantities.

Thermal expansion coefficients of a binary alloy Ni80Zr20 at elevated temperatures

1984 ◽  
Vol 17 (5) ◽  
pp. 359-360
Author(s):  
S. K. Shadangi ◽  
U. K. Shadangi ◽  
S. C. Panda
Keyword(s):  
Thermal Expansion ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Elevated Temperatures ◽  
Intermetallic Phase ◽  
Lattice Parameter ◽  
Solid Solution Phase ◽  
Linear Variation ◽  
Thermal Expansion Coefficients ◽  
Expansion Coefficients

The Debye–Scherrer pattern of the alloy Ni80Zr20 clearly shows the presence of a nickel solid-solution phase along with a new intermetallic phase Ni23Zr6, which seems to be isostructural with the Co23Zr6 phase. The thermal expansion coefficient of the Ni23Zr6 phase has been investigated in the temperature range 1003–1493 K. Linear variation of lattice parameter with temperature has been observed. The thermal expansion coefficient remains almost constant throughout this temperature interval.

Fabrication and Characterization of Low Thermal Expansion Cordierite/Spodumene/Mullite Composite Ceramic for Cookware

2018 ◽  
Vol 766 ◽  
pp. 276-281
Author(s):  
Pranee Junlar ◽  
Thanakorn Wasanapiarnpong ◽  
Lada Punsukmtana ◽  
Noppasint Jiraborvornpongsa
Keyword(s):  
Thermal Expansion ◽  
Water Absorption ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Coefficient Of Thermal Expansion ◽  
Slip Casting ◽  
Ceramic Composites ◽  
Modulus Of Rupture ◽  
Mullite Phase ◽  
Low Thermal Expansion

Ceramic cookware can be taken a direct flame or stove top for the duration without damage. The selected materials must have low thermal expansion coefficient, high strength, low water absorption and high thermal shock resistance, reasonable in cost and easy to be produced. Cordierite and spodumene composite has been interested for ceramic cookware due to their fitted properties. In previous work, study in the cordierite-spodumene composite with low thermal expansion coefficient of 2.60 x 10-6 /°C when sintered at 1250 oC with a ratio of spodumene 60 wt% and cordierite 40 wt% can withstand the pot shape samples. However, the sample showed relatively high water absorption and low strength which was not appropriate for using in this application. In this research, mullite is added in the formula to improve strength and densification of ceramic composites. Spodumene, ball clay, calcined talc and calcined alumina are used as starting raw materials and formed by slip casting. All samples are sintered in a temperature range from 1250-1275 °C in an electric furnace. Water absorption and bulk density were tested by Archimedes method, modulus of rupture was tested by the three-point bending method, microstructure were investigated by SEM and the coefficient of thermal expansion was measured by dilatometer. It was found that the mullite phase was investigated when adding mullite more than 30 wt% in cordierite-spodumene composite.

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