Author: Bamidele S. AllimiPublisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
Metal-insulator Transition in Epitaxial V2O3 Thin Films
Author: Bamidele S. AllimiStudy of the Metal-insulator Transition in LaCoO3-x Epitaxial Films
Author: Lindsey Erin NoskinLattice Distortion of V2O3 Thin Films During Metal-to-insulator Transition
Author: Ziming ShaoPublisher:
ISBN:
Category :
Languages : en
Pages : 55
Book Description
As a prototypical Mott-Hubbard system, bulk vanadium sesquioxide (V2O3), undergoes a first-order Metal-to-Insulator Transition (MIT) from the paramagnetic metallic phase to an antiferromagnetic insulator phase upon cooling to ~160K. Along with MIT, a structural phase transition from rhombohedral to monoclinic structure happens around the same temperature. In the past few decades, the transition temperature of V2O3 has been successfully modified by tens of degrees by introducing lattice strain (through doping, heteroepitaxial growth, etc.). However, how the lattice strain affects the structural distortion and MIT remains elusive to this day. In this work, we studied the lattice distortion of V2O3 thin films heteroepitaxially grown on variously oriented sapphire substrates through X-ray diffraction at Cornell High Energy Synchrotron Source (CHESS). We show that the in-plane biaxial strain drastically affects the intrinsic lattice distortions and the microstrain states in films. Besides, an intermediate interfacial structure was observed in the film grown on (100)-oriented substrate, which is a plausible model for explaining the recent discovery of a memory effect in electrical transport properties of V2O3.
Epitaxial Growth of La-Ca-Mn-O Thin Films with Ultra-sharp Metal-insulator Transition
Author: Chi Hung LeungPublisher:
ISBN:
Category : Magnetoresistance
Languages : en
Pages :
Book Description
Thickness-dependent Metal-insulator Transition in Epitaxial SrRuO3 Ultrathin Films
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Transport characteristics of ultrathin SrRuO3 films, deposited epitaxially on TiO2-terminated SrTiO3 (001) single-crystal substrates, were studied as a function of film thickness. Evolution from a metallic to an insulating behavior is observed as the film thickness decreases from 20 to 4 unit cells. In films thicker than 4 unit cells, the transport behavior obeys the Drude low temperature conductivity with quantum corrections, which can be attributed to weak localization. Fitting the data with 2-dimensional localization model indicates that electron-phonon collisions are the main inelastic relaxation mechanism. In the film of 4 unit cells in thickness, the transport behavior follows variable range hopping model, indicating a strongly localized state. As a result, magnetoresistance measurements reveal a likely magnetic anisotropy with the magnetic easy axis along the out-of-plane direction.
The Solid-solid Phase Transition in Vanadium Dioxide Thin Films
Author: Joyeeta NagPublisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages : 192
Book Description
Epitaxial Oxide Thin Films
Author: Metal-insulator Transition in Low Dimensional La{sub 0.75}Sr{sub 0.25}VO3 Thin Films
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
We report on the metal-insulator transition that occurs as a function of film thickness in ultrathin La{sub 0.75}Sr{sub 0.25}VO3 films. The metal-insulator transition displays a critical thickness of 5 unit cell. Above the critical thickness, metallic films exhibit a temperature driven metal-insulator transition with weak localization behavior. With decreasing film thickness, oxygen octahedron rotation in the films increases, causing enhanced electron-electron correlation. The electronelectron correlations in ultrathin films induce the transition from metal to insulator in addition to Anderson localization.
Epitaxial Oxide Thin Films and Heterostructures
Author: Epitaxial Oxide Thin Films II: Volume 401
Author: James S. SpeckPublisher:
ISBN:
Category : Science
Languages : en
Pages : 588
Book Description
Our understanding and control of epitaxial oxide heterostructures has progressed along multiple frontiers including magnetic, dielectric, ferroelectric, and superconducting oxide materials. This has resulted in both independent rediscovery and the successful borrowing of ideas from ceramic science, solid-state physics, and semiconductor epitaxy. A new field of materials science has emerged which aims at the use of the intrinsic properties of various oxide materials in single-crystal thin-film form. Exploiting the potential of these materials, however, will only be possible if many fundamental and engineering questions can be answered. This book represents continued progress toward fulfilling that promise. Technical information on epitaxial oxide thin films from industry, academia and government laboratories is presented. Topics include: dielectrics; ferroelectrics; optics; superconductors; magnetics; magnetoresistance.