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Title: Oxide Ferromagnetic Semiconductors for Spin-Electronic Transprt

Abstract

The objective of this research was to investigate the viability of oxide magnetic semiconductors as potential materials for spintronics. We identified some members of the solid solution series of ilmenite (FeTiO3) and hematite (Fe2O3), abbreviated as (IH) for simplicity, for our investigations based on their ferromagnetic and semiconducting properties. With this objective in focus we limited our investigations to the following members of the modified Fe-titanates: IH33 (ilmenitehematite with 33 atomic percent hematite), IH45 (ilmenite-hematite with 45 atomic percent hematite), Mn-substituted ilmenite (Mn-FeTiO3), and Mn-substituted pseudobrookite (Mn- Fe2TiO5). All of them are: 1. wide bandgap semiconductors with band gaps ranging in values between 2.5 to 3.5 eV; 2. n-type semiconductors; 3.they exhibit well defined magnetic hysteresis loops and 4. their magnetic Curie points are greater than 400K. Ceramic, film and single crystal samples were studied and based on their properties we produced varistors (also known as voltage dependent resistors) for microelectronic circuit protection from power surges, three-terminal microelectronic devices capable of generating bipolar currents, and an integrated structured device with controlled magnetic switching of spins. Eleven refereed journal papers, three refereed conference papers and three invention disclosures resulted from our investigations. We also presented invited papers in three international conferencesmore » and one national conference. Furthermore two students graduated with Ph.D. degrees, three with M.S. degrees and one with B.S. degree. Also two post-doctoral fellows were actively involved in this research. We established the radiation hardness of our devices in collaboration with a colleague in an HBCU institution, at the Cyclotron Center at Texas A&M University, and at DOE National Labs (Los Alamos and Brookhaven). It is to be appreciated that we met most of our goals and expanded vastly the scope of research by including investigations of Mn-FeTiO3, Mn-Fe2TiO5 and by producing a novel three terminal device capable of generating bipolar currents besides producing radiation resistant varistors and a magnetically switchable device. Furthermore we conclusively established the radiation hardness of the four modified iron titanates we studied. In all our publications, conference and seminar presentations, dissertations and theses sponsorship of DOE has been acknowledged« less

Authors:
;  [1];
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Publication Date:
Research Org.:
The University of Alabama, Tuscaloosa, AL
Sponsoring Org.:
USDOE Office of Science and Technology (EM-50)
OSTI Identifier:
941537
Report Number(s):
Revised Final Report
none; TRN: US1001496
DOE Contract Number:  
FG02-03ER46039
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; CURIE POINT; CYCLOTRONS; HARDNESS; HEMATITE; HYSTERESIS; ILMENITE; INVENTIONS; IRON; MAGNETIC SEMICONDUCTORS; MICROELECTRONIC CIRCUITS; MICROELECTRONICS; MONOCRYSTALS; OXIDES; RADIATIONS; RESISTORS; SEMICONDUCTOR RESISTORS; SOLID SOLUTIONS; SURGES; TITANATES; VIABILITY; spintronics, room temperature magnetic-semicondctors, ilmenite-hematite, modified iron titantes, radhard electronics, varistors, nvoel 3-terminal current-voltage device, bipolar current and integrated structured magnetically controlled spin switching.

Citation Formats

Dr. R. K. Pandey, Cudworth Endowed Professor, Professor Emeritus of The Unviersity of Alabama), and Ingram Endowed Professor, Ingram School of Engineering and Physics Department, Texas State University, San Marocs, TX78666. Oxide Ferromagnetic Semiconductors for Spin-Electronic Transprt. United States: N. p., 2008. Web. doi:10.2172/941537.
Dr. R. K. Pandey, Cudworth Endowed Professor, Professor Emeritus of The Unviersity of Alabama), & Ingram Endowed Professor, Ingram School of Engineering and Physics Department, Texas State University, San Marocs, TX78666. Oxide Ferromagnetic Semiconductors for Spin-Electronic Transprt. United States. https://doi.org/10.2172/941537
Dr. R. K. Pandey, Cudworth Endowed Professor, Professor Emeritus of The Unviersity of Alabama), and Ingram Endowed Professor, Ingram School of Engineering and Physics Department, Texas State University, San Marocs, TX78666. Mon . "Oxide Ferromagnetic Semiconductors for Spin-Electronic Transprt". United States. https://doi.org/10.2172/941537. https://www.osti.gov/servlets/purl/941537.
@article{osti_941537,
title = {Oxide Ferromagnetic Semiconductors for Spin-Electronic Transprt},
author = {Dr. R. K. Pandey, Cudworth Endowed Professor and Professor Emeritus of The Unviersity of Alabama) and Ingram Endowed Professor, Ingram School of Engineering and Physics Department, Texas State University, San Marocs, TX78666},
abstractNote = {The objective of this research was to investigate the viability of oxide magnetic semiconductors as potential materials for spintronics. We identified some members of the solid solution series of ilmenite (FeTiO3) and hematite (Fe2O3), abbreviated as (IH) for simplicity, for our investigations based on their ferromagnetic and semiconducting properties. With this objective in focus we limited our investigations to the following members of the modified Fe-titanates: IH33 (ilmenitehematite with 33 atomic percent hematite), IH45 (ilmenite-hematite with 45 atomic percent hematite), Mn-substituted ilmenite (Mn-FeTiO3), and Mn-substituted pseudobrookite (Mn- Fe2TiO5). All of them are: 1. wide bandgap semiconductors with band gaps ranging in values between 2.5 to 3.5 eV; 2. n-type semiconductors; 3.they exhibit well defined magnetic hysteresis loops and 4. their magnetic Curie points are greater than 400K. Ceramic, film and single crystal samples were studied and based on their properties we produced varistors (also known as voltage dependent resistors) for microelectronic circuit protection from power surges, three-terminal microelectronic devices capable of generating bipolar currents, and an integrated structured device with controlled magnetic switching of spins. Eleven refereed journal papers, three refereed conference papers and three invention disclosures resulted from our investigations. We also presented invited papers in three international conferences and one national conference. Furthermore two students graduated with Ph.D. degrees, three with M.S. degrees and one with B.S. degree. Also two post-doctoral fellows were actively involved in this research. We established the radiation hardness of our devices in collaboration with a colleague in an HBCU institution, at the Cyclotron Center at Texas A&M University, and at DOE National Labs (Los Alamos and Brookhaven). It is to be appreciated that we met most of our goals and expanded vastly the scope of research by including investigations of Mn-FeTiO3, Mn-Fe2TiO5 and by producing a novel three terminal device capable of generating bipolar currents besides producing radiation resistant varistors and a magnetically switchable device. Furthermore we conclusively established the radiation hardness of the four modified iron titanates we studied. In all our publications, conference and seminar presentations, dissertations and theses sponsorship of DOE has been acknowledged},
doi = {10.2172/941537},
url = {https://www.osti.gov/biblio/941537}, journal = {},
number = ,
volume = ,
place = {United States},
year = {2008},
month = {11}
}