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Author Jena, Sushree Sangita ♦ Rout, G. C. ♦ Panda, S. K.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS ♦ ANISOTROPY ♦ COUPLING ♦ ELASTICITY ♦ ELECTRONS ♦ FREE ENERGY ♦ GREEN FUNCTION ♦ HAMILTONIANS ♦ IRON COMPOUNDS ♦ JAHN-TELLER EFFECT ♦ LATTICE PARAMETERS ♦ OCCUPATION NUMBER ♦ ORTHORHOMBIC LATTICES ♦ PHASE TRANSFORMATIONS ♦ PNICTIDES ♦ POTENTIALS ♦ SPECIFIC HEAT ♦ STRAINS ♦ TEMPERATURE DEPENDENCE
Abstract We attribute the structural phase transition (SPT) in the parent compounds of the iron pnictides to orbital ordering. Due to anisotropy of the d{sub xz} and d{sub yz} orbitals in the xy plane, orbital ordering makes the orthorhombic structure more favorable and thus inducing the SPT. We consider a one band model Hamiltonian consisting of first and second-nearest-neighbor hopping of the electrons. We introduce Jahn-Tellar (JT) distortion in the system arising due to the orbital ordering present in this system. We calculate the electron Green’s function by using Zuvareb’s Green’s function technique and hence calculate an expression for the temperature dependent lattice strain which is computed numerically and self-consistently. The temperature dependent electron specific heat is calculated by minimizing the free energy of the system. The lattice strain is studied by varying the JT coupling and elastic constant of the system. The structural anomaly is studied through the electron occupation number and the specific heat by varying the physical parameters like JT coupling, lattice constant, chemical potential and hopping integrals of the system.
ISSN 0094243X
Educational Use Research
Learning Resource Type Article
Publisher Date 2016-05-06
Publisher Place United States
Volume Number 1728
Issue Number 1


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