GaN films were grown on (100) GaAs substrates by metalorganic chemical vapor deposition and were found to be of (200) cubic or (111) cubit/(0002) hexagonal phase. Their photoluminescence characteristics remained invariant with material phase. We report assignment of band-edge photoluminescence near 3!36 eV and 3.15-3.31 eV in apparently cubic GaN to intrinsic/bound excitons and phonon-assisted,...

We report detailed experimental studies on the rheology of cubic blue phases. We observe several flow regimes within each blue phase from rheomicroscopy and small angle light scattering experiments. Both the cubic blue phases exhibit solid-like response while the cholesteric phase shows gel-like behavior. The elastic modulus of BP-I is larger than that of BP-II. The shear induced yield transiti...

II-VI compound semiconductors, ZnS, ZnSe, CdS, CdSe, and CdTe, were grown epitaxially on ~111! and ~100! InP and GaAs substrates by excimer laser ablation. All of these films have good crystalline quality ~fully in-plane aligned! and mirror-like surface morphology. It was found that, on ~111!-oriented substrates, CdS and CdSe films were in the hexagonal phase with the c axis perpendicular to th...

Cubic Li7La3Zr2O12 (LLZO) garnets are exceptionally well suited to be used as solid electrolytes or protecting layers in "Beyond Li-ion Battery" concepts. Unfortunately, cubic LLZO is not stable at room temperature (RT) and has to be stabilized by supervalent dopants. In this study we demonstrate a new possibility to stabilize the cubic phase at RT via substitution of Zr(4+) by Mo(6+). A Mo(6+)...

A finite element approximation of the thin film limit for a sharp interface bulk energy for martensitic crystals is given. The energy density models the softening of the elastic modulus controlling the low-energy path from the cubic to the tetragonal lattice, the loss of stability of the tetragonal phase at high temperatures and the loss of stability of the cubic phase at low temperatures, and ...

Obtaining well ordered crystals of membrane proteins is the single most serious stumbling block in the pursuit of their high-resolution structures. The applicability of lipidic cubic phase-mediated crystallization is demonstrated on a diverse set of bacterial membrane proteins: two photosynthetic reaction centres, a light-harvesting complex and two retinal proteins, halorhodopsin and bacteriorh...

Systematic studies on three dimensionally ordered liquid crystalline phases of different cubic and tetragonal symmetries are presented. The structures of the phases are determined by reconstruction of the electron density distribution from the X-ray diffraction patterns. The known models for electron densities in cubic structures were used whereas a new theoretical model for the structure of th...

A study of the magnetic and structural properties of the double perovskite Ba2GdMoO6 has been performed. The crystal structure distorts from the ideal cubic (Fm3m) structure to the tetragonal space group I4/m at 220 K, before undergoing a second distortion to a triclinic system (I1) at 80 K. The phase transition to triclinic symmetry is also evident in magnetic susceptibility measurements. The ...

The lower Wythoff sequence a = (a(n)) and upper Wythoff sequence b = (b(n)) are solutions of many complementary equations f(a, b) = 0. Typically, f(a, b) involves composites such as a(a(n)) and a(b(n)), and each such sequence is treated as a binary word (e.g., aa and ab). Conversely, each word represents a sequence and, as such, is a linear combination of a, b, and 1, in which the coefficients ...

Alumina nanomaterials were synthesized via a solution combustion technique using tris-(acetylacetonato) aluminum(III) complex (1) and tris-(2-formylphenolate) aluminum(III) complex (2) at 600, and 1000 °C for 3h. The obtained data showed that the procedure without using fuel resulted in a better phase and morphology. To investigate the phase formation, powder X-ray diffraction technique was use...