Author: Chi Hung LeungPublisher:
ISBN:
Category : Magnetoresistance
Languages : en
Pages :
Book Description
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
Preparation and Properties of Epitaxial Thin Films of La1-Xbaxmn03 on Various Substrated
Author: Ngai-Shek SoongPublisher: Open Dissertation Press
ISBN: 9781361192412
Category :
Languages : en
Pages :
Book Description
This dissertation, "Preparation and Properties of Epitaxial Thin Films of La1-xBaxMn03 on Various Substrated" by Ngai-shek, Soong, 宋毅碩, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Abstract of thesis entitled PREPARATION AND PROPERTIES OF EPITAXIAL THIN FILMS OF La Ba MnO ON VARIOUS SUBSTRATES 1-x x 3 submitted by Ngai-Shek SOONG for the degree of Master of Philosophy at The University of Hong Kong in December 2002 Epitaxial thin films of La Ba MnO (LBMO) were on deposited SrTiO 0.8 0.2 3 3 (100) (STO), LaAlO (100) (LAO), MgO (100) and Y O - ZrO (100) (YSZ) 3 2 3 2 substrates by using an off-axis magnetron sputtering. The properties of fabricated LBMO thin films were studied by using X-ray diffraction, dc four-probe measurements, surface profiler and atomic force microscopy. For LBMO thin films grown on STO, X-ray diffraction patterns showed that the films were highly c-axis oriented and fully epitaxial. The obtained values of full width at half maximum (FWHM) of the (002) rocking curves were small, indicating good crystallinity of the films. The temperature of insulator-metal transition, T, decreased as the thickness of the thin film increased. This was different from other systems with similar perovskite structure such as La Ca MnO and La Sr MnO . The electrical 1-x x 3 1-x x 3 resistivity of LBMO/STO thin film for temperature T2 4.5 expression of ρ(T) =ρ +ρ T +ρ T (Eq.1). The values of ρ ρ ρ all increased 0 2 4.5 0, 2, 4.5 with increasing thickness d, except d=350A, implying a phase transition may have occured. The anomalous electrical behavior of LBMO/STO system could not be explained by considering only the decreasing of transfer integral on in-plane e electrons. The orbital degree of freedom played a crucial role in determining the electrical properties of tensile-stressed LBMO thin films due to the relatively large ratio of c/a. For LBMO/LAO thin films, X-ray diffraction patterns and small FWHM values implied good crystallinity of the thin films. The decreasing value of out-of- plane lattice parameters with increasing thickness suggested the existence of compressive strain within the LBMO/LAO system. The temperature dependence of resistivity measurement showed that T decreases as the thickness of thin film increased. This is consistent with the double-exchange theory, which states that compressive strain enhances T . The temperature dependence of resistivity of LBMO/LAO thin films were also fitted well to expression (Eq.1), The values of ρ 0, ρ ρ all increased with increased thickness. 2, 4.5 La Ba MnO was also deposited on YSZ or MgO substrates respectively, 0.8 0.2 3 which having larger lattice mismatch. Peaks other than (00l) orientation were observed in X-ray measurements indicating the thin films were c-axis oriented but not highly epitaxial. A fairly large value of the FWHM of the (002) diffraction peak suggested that the films were highly crystalline. Insulator-metal (I-M) transition were not observed in LBMO/MgO films and only appear in LBMO/YSZ films with d>1200A. These were mainly due to that large lattice mismatches between LBMO and YSZ or MgO substrates which generate a large number of grains and grain boundaries in the thin films, which in turn decrease the electron transfer integral. DOI: 10.5353/th_b2663683 Subjects: Thin films Epitaxy
Study of the Metal-insulator Transition in LaCoO3-x Epitaxial Films
Author: Lindsey Erin NoskinMetal-insulator Transition in Epitaxial V2O3 Thin Films
Author: Bamidele S. AllimiColossal Magnetoresistive Manganites
Author: Tapan ChatterjiPublisher: Springer Science & Business Media
ISBN: 9781402018442
Category : Science
Languages : en
Pages : 468
Book Description
This book is a comprehensive account of the present understanding of an important class of perovskite oxide materials with potential industrial applications. The chapters are written by well-known scientists who are on the forefront of the field and have directly contributed to its recent progress. Special care has been taken to maintain a balance between the space devoted to new experimental results and that devoted to recent theoretical developments. The book contains recent experimental and theoretical results on colossal magnetoresistive (CMR) manganites not covered by any other book in the field, and hence this will be very beneficial to graduate students and researchers in condensed matter and applied physics, materials science and solid state chemistry.
Physics of Manganites
Author: T.A. KaplanPublisher: Springer Science & Business Media
ISBN: 0306461323
Category : Science
Languages : en
Pages : 299
Book Description
This series of books, which is published at the rate of about one per year, addresses fundamental problems in materials science. The contents cover a broad range of topics from small clusters of atoms to engineering materials and involves chemistry, physics, materials science and engineering, with length scales ranging from Ångstroms up to millimeters. The emphasis is on basic science rather than on applications. Each book focuses on a single area of current interest and brings together leading experts to give an up to date discussion of their work and the work of others. Each article contains enough references that the interested reader can access the relevant literature. Thanks are given to the Center for Fundamental Materials Research at Michigan State University for supporting this series. M. F. Thorpe, Series Editor E mail: thorpe@pa. msu. edu V PREFACE This book records invited lectures given at the workshop on Physics of Manganites, held at Michigan State University, July 26 29, 1998. Doped manganites are an interesting class of compounds that show both metal insulator and ferromagnetic to paramagnetic transitions at the same temperature. This was discovered in the early 1950s by Jonker and van Santen and basic theoretical ideas were developed by Zener (1951), Anderson and Hasegawa (1955), and deGennes (1960) to explain these transitions and related interesting observations.
Modern Technologies for Creating the Thin-film Systems and Coatings
Author: Nikolay NikitenkovPublisher: BoD – Books on Demand
ISBN: 953513003X
Category : Science
Languages : en
Pages : 446
Book Description
Development of the thin film and coating technologies (TFCT) made possible the technological revolution in electronics and through it the revolution in IT and communications in the end of the twentieth century. Now, TFCT penetrated in many sectors of human life and industry: biology and medicine; nuclear, fusion, and hydrogen energy; protection against corrosion and hydrogen embrittlement; jet engine; space materials science; and many others. Currently, TFCT along with nanotechnologies is the most promising for the development of almost all industries. The 20 chapters of this book present the achievements of thin-film technology in many areas mentioned above but more than any other in medicine and biology and energy saving and energy efficiency.
Physics Briefs
Author: Atomic Layer Deposition for Semiconductors
Author: Cheol Seong HwangPublisher: Springer Science & Business Media
ISBN: 146148054X
Category : Science
Languages : en
Pages : 266
Book Description
Offering thorough coverage of atomic layer deposition (ALD), this book moves from basic chemistry of ALD and modeling of processes to examine ALD in memory, logic devices and machines. Reviews history, operating principles and ALD processes for each device.
Pulsed Laser Deposition of Thin Films
Author: Robert EasonPublisher: John Wiley & Sons
ISBN: 0470052112
Category : Science
Languages : en
Pages : 754
Book Description
Edited by major contributors to the field, this text summarizes current or newly emerging pulsed laser deposition application areas. It spans the field of optical devices, electronic materials, sensors and actuators, biomaterials, and organic polymers. Every scientist, technologist and development engineer who has a need to grow and pattern, to apply and use thin film materials will regard this book as a must-have resource.