Structure D 2000Crystal Structure Refinement of the Ternary Compound Cu2SnTe3 by X-Ray Powder Diffraction. -The crystal structure of the title compound is refined from powder XRD data using the Rietveld method. Cu2SnTe3 crystallizes in the space group Imm2 with Z = 2. The compound is isostructural with Cu2GeSe3 and consists of a three-dimensional arrangement of slightly distorted CuTe4 and SnTe4 tetrahedra connected by common corners. -(DELGADO*, G. E.; MORA, A. J.; MARCANO, G.; RINCON, C.; Cryst.
This work is a study of the microstructural properties of the polycrystalline ternary compounds AgIn 5 S 8 , AgIn 5 Se 8 , and AgIn 5 Te 8 by X-ray diffraction technique (XRD). The full-width-half-maximum (FWHM) of the XRD profile is measured as function of the diffraction angle and used to estimate the microstructural parameters. In general, a microstructural characterization by XRD is principally performed by Strain/Size analysis based on the modified Scherrer formula, which in turn, allows for mean grain size and average microstrain to be computed. However, when applied to polycrystalline bulk semiconductors, the modified Scherrer formula gives grain sizes of the order of a few hundreds of nanometers, which is not usually observed in bulk materials. Instead, a new theoretical scheme with misfit dislocations and plastic deformations would be used to calculate the grain size into a bulk. Assuming that these dislocations are of elastic origin, we were able to calculate the misfit dislocations density as function of the elastic constants of the materials. With this, the modified Scherrer formula is corrected to explain the additional XRD line broadening. All microstructure parameters of our samples increase as the atomic radius of the VI-element increases, with elastic constants similar to related semiconducting compounds.
Temperature and field dependence of the magnetic behavior of magnetic moments of the rare earth and Mn sublattices of RMn2Ge2, where R is a rare earth element, leads to a variety of interesting magnetic properties. These compounds crytallise in the tetragonal ThCr2Si2 type crystal structure with space group I4/mmm which consist of layers along the c-axis with sequence R-Ge-Mn-Ge-R. When light rare-earth elements ( Pr, La, Ce or Nd) use in title compounds, the interlayer magnetic coupling in the Mn sublattice is ferromagnetic, whereas it is antiferromagnetic in the case of Gd, Tb or Dy. At low temperatures, the rare earth sublattice also orders and reconfigures the ordering in the Mn sublattice. In this study, crystal structure and magnetic properties of Pr1-xTbxMn2Ge2 compounds were investigated by X-ray diffraction and magnetic measurements. The results of earlier neutron diffraction and Mössbauer studies on samples with x = 0 and x = 1 are also used for interpreting the magnetization data and to give an account on the competing effects between various magnetic structures in the Mn and rare earth sublattices. In low field, we have observed that, temperature dependence of zero field cooled and field cooled magnetizations shows large difference at the Curie temperature of Mn sublattices (TC). This behavior is related to pinnnig of the ferromagnetic components of Mn sublattices and proved that there is an antiferromagnetic ordering of Mn sublattices with Neel temperature TN > TC,which has been observed only by using neutron diffraction techniques.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.