Processing and Optimization of Bulk La₁₋ₓCaₓMnO3±δ.

The following explores the first systematic research conducted at Texas A&M University studying preparation techniques of the bulk La1-x-Cax-Mn-O3"d colossal magnetoresistance (CMR) family. Three sample sets of La1-x-Cax-Mn-O3"d were fabricated using different preparation techniques....

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Bibliographic Details
Main Authors: Ybarra, Ignacio, III, Ybarra, Ignacio III
Corporate Author: Texas A & M University. University Undergraduate Research Fellow Program
Format: Thesis Book
Language:English
Published: [College Station, Texas] : Texas A&M University, 1998.
Subjects:
Online Access:Link to OAK Trust copy
Available on OAKTrust.
Description
Summary:The following explores the first systematic research conducted at Texas A&M University studying preparation techniques of the bulk La1-x-Cax-Mn-O3"d colossal magnetoresistance (CMR) family. Three sample sets of La1-x-Cax-Mn-O3"d were fabricated using different preparation techniques. Details of each technique and the subsequent sample characterization are presented. Focus of the study was directed to compositions in the range 0.25<x<0.5 because these compositions exhibit a insulator-to-metal transition associated with the paramagnetic-to-ferromagnetic (FM) transition upon cooling. Resistance, susceptibility, x-ray diffraction, and BSE photograph data is presented and compared for compositions of different sample sets.
In all three sets, unexpected trends and inconsistencies in resistance and susceptibility were observed. BSE photographs confirm sample inhomogeneity, although WDS and x-ray diffraction data suggests that the bulk of the samples are the correct composition. Future changes in preparation techniques are explored. In conclusion, more research is needed to optimize reaction/annealing temperatures and duration parameters to fabricate more homogeneous bulk La1-x-Cax-Mn-O3"d magnetoresistance materials.
Item Description:"Major Subject: Engineering I".
On title page "x" and "±" are in subscript.
Physical Description:1 online resource (37 pages).
Digitized from print version held at Pickle Center High Density Storage, barcode 24829659
Bibliography:Includes bibliographical references: leaf 34.