Potential existence of post-perovskite nitrides; DFT studies of ThTaN{sub 3}

Journal Article · Sat May 15 00:00:00 EDT 2010 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2010.03.002· OSTI ID:21372584

Demazeau, Gerard ^[1]

---

1. CNRS, Universite de Bordeaux, ICMCB, 87 avenue Dr Albert Schweitzer, 33600 Pessac (France)

Within density functional theory, the equations of state for cubic perovskite (c-PV) and hypothetic orthorhombic perovskite (o-PV GdFeO{sub 3}-type) and post-perovskite (PPV) forms of ThTaN{sub 3} are obtained. The decreasing volume and stabilizing energy indicate pressure enabled transitions: c-PV ->o-PV ->PPV. From electronic structure analysis the chemical system is found insulating in the c-PV ground state form with {approx}1eV band gap and semi-conducting for the PPV due to increased covalence. The chemical bonding properties show that Th and Ta bondings with the 2 N sites are selectively differentiated and reinforced for Ta-N bond within PPV form. This is the consequence of the corner as well as edge sharing octahedra characterizing PPV while PV structures have only corner sharing octahedra. It is the first case of potential post-perovskite nitride. - ThTaN{sub 3}: Projected charge density (for 4 fu) onto basal plane: (a) cubic perovskite, (b) orthorhombic perovskite and (c) post-perovskite. Red, green and blue areas are relevant to strong, medium and low localization of density.

• OSTI ID: 21372584
• Journal Information: Journal of Solid State Chemistry, Vol. 183, Issue 5; Other Information: DOI: 10.1016/j.jssc.2010.03.002; PII: S0022-4596(10)00078-2; Copyright (c) 2010 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CHARGE DENSITY
CHEMICAL BONDS
CUBIC LATTICES
DENSITY FUNCTIONAL METHOD
ELECTRONIC STRUCTURE
EQUATIONS OF STATE
GROUND STATES
NITRIDES
ORTHORHOMBIC LATTICES
PEROVSKITE
TANTALUM COMPOUNDS
THALLIUM COMPOUNDS
CALCULATION METHODS
CRYSTAL LATTICES
CRYSTAL STRUCTURE
ENERGY LEVELS
EQUATIONS
MINERALS
NITROGEN COMPOUNDS
OXIDE MINERALS
PEROVSKITES
PNICTIDES
REFRACTORY METAL COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
VARIATIONAL METHODS