相关论文: Twin model for orthorhombic perovskites

A model for diffusion on a cubic lattice with a random distribution of traps is developed. The traps are redistributed at certain time intervals. Such models are useful for describing systems showing dynamic disorder, such as ion-conducting…

Oriented circular cylinders in an opaque medium are used to represent certain microstructural objects in steel. The opaque medium is sliced parallel to the cylinder axes of symmetry and the cut-plane contains the observable rectangular…

We present a simplified model for dynamical diffraction of particles through a periodic thick perfect crystal based on repeated application of a coherent beam splitting unitary at coarse-grained lattice sites. By demanding translational…

We report temperature and thermal-cycling dependence of surface and bulk structures of double-layered perovskite Sr3Ru2O7 single crystals. The surface and bulk structures were investigated using low-energy electron diffraction (LEED) and…

We study theoretically the phase diagram of the double-layered perovskite manganites taking into account the orbital degeneracy, the strong Coulombic repulsion, and the coupling with the lattice deformation. Observed spin structural changes…

The current theory of twin crystallography is based on the concept of invariant plane. The present paper extends the theory to encompass the cases of heterotwins in which the composition plane is only quasi-invariant.

Multiply twinned particles, MTPs, are fascinating crystallographic entities with a number of controllable properties originating from their symmetry and cyclic structure. In the focus of our studies are diamond MTPs hosting optically active…

We describe a first open-access database of experimentally investigated hybrid organic-inorganic materials with two-dimensional (2D) perovskite-like crystal structure. The database includes 515 compounds, containing 180 different organic…

Understanding the processes of perovskite crystallization is essential for improving the properties of organic solar cells. In situ real-time grazing-incidence X-ray diffraction (GIXD) is a key technique for this task, but it produces large…

The application of powder diffraction methods in two-dimensional crystallography is regarded as intractable because of the uncertainties associated with overlapping reflections. Here, we report an approach that resolves these ambiguities…

We extend our previous theoretical study of Mn-based orthorhombic metamagnets to those that possess large nearest neighbour Mn-Mn separations (d1>3.22A). Based on our calculations, we design and synthesize a series of alloys,…

Synchrotron x-ray powder diffraction measurements have been performed on unpoled ceramic samples of (1-x)PbMg(1/3)Nb(2/3)O3-xPbTiO3 (PMN-xPT) with 30%<= x<= 39% as a function of temperature around the morphotropic phase boundary (MPB),…

A single crystal of GdBaCo2O5.47(2) has been studied by means of X-ray diffraction. Appearance of superstructure reflections at T = 341.5(7) K gives an evidence of continuous transition to the phase with unit cell doubled along the shortest…

Friedel's law guarantees an inversion-symmetric diffraction pattern for thin, light materials where a kinematic approximation or a single-scattering model holds. Typically, breaking Friedel symmetry is ascribed to multiple scattering events…

The x-ray diffraction (XRD) patterns reported for starch in the literature describes it as a semicrystalline polymer that indicates that amorphous and crystalline regions form it, and this is commonly accepted. However, these patterns have…

The diffraction of stochastic point sets, both Bernoulli and Markov, and of random tilings with crystallographic symmetries is investigated in rigorous terms. In particular, we derive the diffraction spectrum of 1D random tilings, of…

Double perovskites of the form A_2BB'O_6 usually involve a transition metal ion, B, with a large magnetic moment, and a non magnetic ion B'. While many double perovskites are ferromagnetic, studies on the underlying model reveal the…

Twisting and stacking two copies of a 2D crystal can produce a long-wavelength periodic interference pattern known as a moir\'e pattern. Performing the same procedure with an aperiodic structure instead generates a single moir\'e spot at…

While performing molecular dynamics simulations of a simple monatomic liquid, we observed the crystallization of a material displaying octagonal symmetry in its simulated diffraction pattern. Inspection of the atomic arrangements in the…

Large single crystals of the double-perovskite Ba$_2$ScNbO$_6$ were grown from the melt for the first time. With a lattice parameter at room temperature of 4.11672(1) \r{A}, this cubic double-perovskite has an excellent lattice match to…