based on the {s+, i-} pathway, the concentration of surfactant and surface charge density of silanolate groups control the phase transition from lamellar, to hexagonal through cubic form. the high surface charge density of silanolate groups was observed for the lamellar phase. with decrease of molar concentration of surfactant on the gel, the yield of reaction decreases and the stability of mes...

the electronic structure, energy band structure and electronic density of 2 sno ceramic in cubicphase have been investigated using first principle full potential-linearized augmented plane wave (fp-lapw)method within density functional theory (dft). local density approximation (lda) and the generalizedgradient approximation (gga), which are based on exchange- correlation energy optimization wer...

in this study, physical vapor deposition (pvd) ti-cr-n coatings were deposited at two different temperatures100 and 400ºc on hardened and tempered tool steel substrates. the influence of the applied deposition temperature on the physical and mechanical properties of coatings such as roughness, thickness, phase composition, hardness and young’s modulus were evaluated. phase compositions were stu...

in this research work the solid-solutions of (bi2o3)1-x (co2o3)x, [x= 0.05, 0.1] (1), (bi2o3)1-x (ho2o3) x, [x= 0.025, 0.05] (2), and (bi2o3)1-x-y (co2o3)x (ho2o3)y, [x=0.05] ; [y= 0.01, 0.02] (3) have been synthesized  using sol-gel method. the effects of transition metal oxides doping on the crystallization and phase transition of the bi2o3 were discussed by x-ray diffraction (xrd). the xrd p...

The morphology of hexagonal phase NaYF4:Er(3+) nanorods synthesized by hydrothermal method changed greatly after a continuing calcination, along with a phase transformation to cubic phase. Photoluminescence (PL) spectra indicated that mid-infrared (MIR) emission was obtained in both hexagonal and cubic phase NaYF4:Er(3+) nanocrystals for the first time. And the MIR emission of NaYF4:Er(3+) nano...

Both the superelastic and the shape memory properties of the cubic NiTi alloy known as Nitinol arise from two-phase transitions; from a simple cubic austenite phase to a trigonal R-phase and to a lower symmetry martensite phase. In this article, we speculate that two competing forces drive these transitions. One is “mechanical” in nature and it takes the cubic austenite structure of NiTi to a d...