The Development of Alkoxy-Based Sol -Gel Processing for Magnetoresistive Manganite Thin Films

Clothier, Brent Allen

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https://hdl.handle.net/2142/82760 Copy

Description

Title

The Development of Alkoxy-Based Sol -Gel Processing for Magnetoresistive Manganite Thin Films

Author(s)

Clothier, Brent Allen

Issue Date

2005

Doctoral Committee Chair(s)

Payne, David A.

Department of Study

Materials Science and Engineering

Discipline

Materials Science and Engineering

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

Engineering, Materials Science

Language

eng

Abstract

The cubic lattice parameters of the films (i.e., a = ∼ 3.90 A) were in excellent agreement with values published in the literature for bulk, polycrystalline powders. Typical grain sizes started at 10--15 nm, increasing to 20--25 nm by 750°C. For films deposited on Si(100), magnetoresistance was observed in specimens heat treated at 700°C and 750°C, and for platinized-Si(100), 650°C, 700°C, and 750°C. Magnetoresistive response improved with heat-treatment temperature for the more refractory La0.67Ba0.33MnO3 composition. The lead-doped counterpart offered the best property evolution, with TC = 320 K and TIM = 254 K by 750°C on platinized-Si(100). All corresponding transport curves were symmetric, demonstrating clear metal-insulator transitions (i.e., TIM). High resistivities (i.e., ∼ 106 O-cm) were attributed to the fine-grain microstructure. Weak-field cycling between +/-500 Oe yielded symmetrical loops with appreciable linear regions, a highly-desirable characteristic for magnetic sensing applications.

Graduation Semester

2005

Type of Resource

text

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http://hdl.handle.net/2142/82760

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