Structural Characterization and Physical Properties of the New Transition Metal Oxyselenide La₂O₂ZnSe₂

Abstract

The quaternary transition metal oxyselenide La(2)O(2)ZnSe(2) has been shown to adopt a ZrCuSiAs-related structure with Zn(2+) cations in a new ordered arrangement within the [ZnSe(2)](2-) layers. This cation-ordered structure can be derived and described using the symmetry-adapted distortion mode approach. La(2)O(2)ZnSe(2) is an direct gap semiconductor with an experimental optical band gap of 3.4(2) eV, consistent with electronic structure calculations.

Synthesis, Structural Characterization, and Physical Properties of the New Transition Metal Oxyselenide Ce2O2ZnSe2

“…It contains both edge-sharing and corner-sharing ZnSe 4 tetrahedra, leading to alternating "checkerboard-like" and "stripe-like" regions along the a axis. This is similar to the La 2 O 2 ZnSe 2 structure, 15 14 where all cations order in a checkerboard arrangement (1C-0E) of corner-sharing tetrahedra. While Zn ordering is the main driver for the symmetry lowering, there are significant accompanying structural distortions, mainly in the Zn-Se tetrahedra shown in Figure 12 and Figure 13.…”

Structural and magnetic characterization of iron oxyselenidesCe2O2Fe2OSe2andMcCabe1, Wills2, Chapon3 et al. 2014Phys. Rev. B139260View full textAdd to dashboardCite

“…The approach of directly refining the contributions of the different magnetic basis vectors is similar to that originally developed in SARAh [37]. Mode inclusion analysis [25,38] (see Supplemental Material [33] for more details) indicated no change in the Fe moment arrangement on cooling. A good fit could, however, be obtained with an ordered moment on Ce sites.…”

Bi2W2O9: A potentially antiferroelectric Aurivillius phase

“…The ISODISTORT software [34] was used to consider possible distortions and the "mode inclusion method" [42,43] was employed, using the highest resolution backscattered (169 • ) NPD data, to determine which distortions gave the greatest improvement in fit. This analysis indicated that in-plane antipolar displacements (M + 5 ) and in-plane axis octahedral tilts a − a − c 0 (X − 3 ) gave significant improvements in fit, together lowering the symmetry to P nab.…”