Phosphorus atoms are to be diffused into a silicon wafer Phosphorus atoms are to be diffused into a silicon wafer using both predeposition and drive-in heat treatments; the background concentration of P in this silicon material is known to be 5 ( 1019 atoms/m3. The predeposition treatment is to be conducted at 950째C for 45 […]
The microstructure of a lead-tin alloy at 180oC (355oF) consists The microstructure of a lead-tin alloy at 180oC (355oF) consists of primary β and eutectic structures. If the mass fractions of these two micro constituents are 0.57 and 0.43, respectively, determine the composition of the alloy.
The mechanical properties of aluminum may be improved by incorpo The mechanical properties of aluminum may be improved by incorporating fine particles of aluminum oxide (Al2O3). Given that the moduli of elasticity of these materials are, respectively, 69 GPa (10 ( 106 psi) and 393 GPa (57 ( 106 psi), plot modulus of elasticity versus […]
The diffusion coefficients for iron in nickel are given at The diffusion coefficients for iron in nickel are given at two temperatures: (a) Determine the v The mass fraction of eutectoid cementite in an iron-carbon alloy is 0.104. On the basis of this information, is it possible to determine the composition of the alloy? If […]
The diffusion coefficients for iron in nickel are given at The diffusion coefficients for iron in nickel are given at two temperatures: (a) Determine the values of D0 and the activation energy Qd. (b) What is the magnitude of D at 1100?oC (1373K)?
The diffraction peaks shown in figure are indexed according to The diffraction peaks shown in figure are indexed according to the reflection rules for BCC (i.e., the sum h + k + l must be even). Cite the h, k, and l indices for the first four diffraction peaks for FCC crystals consistent with h, […]
The difference between the specific heats at constant pressure The difference between the specific heats at constant pressure and volume is described by the expression where av is the volume coefficient of thermal expansion, v0 is the specific volume (i.e., volume per unit mass, or the reciprocal of density), Ă is the compressibility, and T […]
The dielectric constant for a soda–lime glass measured at very The dielectric constant for a sodaâlime glass measured at very high frequencies (on the order of 1015 Hz) is approximately 2.3. What fraction of the dielectric constant at relatively low frequencies (1 MHz) is attributed to ionic polarization? Neglect any orientation polarization contributions.
The density and associated percent crystallinity for two polytet The density and associated percent crystallinity for two polytetrafluoroethylene materials are as follows: (a) Compute the densities of totally crystalline and totally amorphous polytetrafluoroethylene. (b) Determine the percent crystallinity of a specimen having a density of 2.26g/cm3.
The corundum crystal structure, found for Al2O3, consists of an The corundum crystal structure, found for Al2O3, consists of an HCP arrangement of O2- ions; the Al3+ ions occupy octahedral positions. (a) What fraction of the available octahedral positions are filled with Al3+ ions? (b) Ketch two close-packed O2âplanes stacked in an AB sequence, and […]