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Title: Dopant Segregation and Giant Magnetoresistance in Manganese-doped Germanium

Abstract

Dopant segregation in a Mn{sub x}Ge{sub 1-x} dilute magnetic semiconductor leads to a remarkable self-assembly of Mn-rich nanocolumns, embedded in a fully compensated Ge matrix. Samples grown at 80 C display a giant positive magnetoresistance that correlates directly with the distribution of magnetic impurities. Annealing at 200 C increases Mn substitution in the host matrix above the threshold for the insulator-metal transition, while maintaining the columnar morphology, and results in global ferromagnetism with conventional negative magnetoresistance. The qualitative features of magnetism and transport in this nanophase material are thus extremely sensitive to the precise location and distribution of the magnetic dopants.

Authors:
 [1];  [1];  [1];  [1];  [1];  [1];  [1];  [1];  [1];  [2];  [1];  [1]
  1. ORNL
  2. South Dakota School of Mines and Technology
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Center for Nanophase Materials Sciences
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
931495
DOE Contract Number:
DE-AC05-00OR22725
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review B; Journal Volume: 75; Journal Issue: 47
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 77 NANOSCIENCE AND NANOTECHNOLOGY; GERMANIUM; DOPED MATERIALS; MANGANESE; PHASE TRANSFORMATIONS; HEAT TREATMENTS; MORPHOLOGY; NANOSTRUCTURES; FERROMAGNETISM; MAGNETORESISTANCE

Citation Formats

Li, An-Ping, Zeng, Changgan, van Benthem, Klaus, Chisholm, Matthew F, Shen, Jian, Rao, Nageswara, Dixit, Suvasis, Feldman, Leonard C, Petukhov, Andre G, Foygel, M., Weitering, Harm H, and Gunter, Sandra Lynn. Dopant Segregation and Giant Magnetoresistance in Manganese-doped Germanium. United States: N. p., 2007. Web. doi:10.1103/PhysRevB.75.201201.
Li, An-Ping, Zeng, Changgan, van Benthem, Klaus, Chisholm, Matthew F, Shen, Jian, Rao, Nageswara, Dixit, Suvasis, Feldman, Leonard C, Petukhov, Andre G, Foygel, M., Weitering, Harm H, & Gunter, Sandra Lynn. Dopant Segregation and Giant Magnetoresistance in Manganese-doped Germanium. United States. doi:10.1103/PhysRevB.75.201201.
Li, An-Ping, Zeng, Changgan, van Benthem, Klaus, Chisholm, Matthew F, Shen, Jian, Rao, Nageswara, Dixit, Suvasis, Feldman, Leonard C, Petukhov, Andre G, Foygel, M., Weitering, Harm H, and Gunter, Sandra Lynn. Mon . "Dopant Segregation and Giant Magnetoresistance in Manganese-doped Germanium". United States. doi:10.1103/PhysRevB.75.201201.
@article{osti_931495,
title = {Dopant Segregation and Giant Magnetoresistance in Manganese-doped Germanium},
author = {Li, An-Ping and Zeng, Changgan and van Benthem, Klaus and Chisholm, Matthew F and Shen, Jian and Rao, Nageswara and Dixit, Suvasis and Feldman, Leonard C and Petukhov, Andre G and Foygel, M. and Weitering, Harm H and Gunter, Sandra Lynn},
abstractNote = {Dopant segregation in a Mn{sub x}Ge{sub 1-x} dilute magnetic semiconductor leads to a remarkable self-assembly of Mn-rich nanocolumns, embedded in a fully compensated Ge matrix. Samples grown at 80 C display a giant positive magnetoresistance that correlates directly with the distribution of magnetic impurities. Annealing at 200 C increases Mn substitution in the host matrix above the threshold for the insulator-metal transition, while maintaining the columnar morphology, and results in global ferromagnetism with conventional negative magnetoresistance. The qualitative features of magnetism and transport in this nanophase material are thus extremely sensitive to the precise location and distribution of the magnetic dopants.},
doi = {10.1103/PhysRevB.75.201201},
journal = {Physical Review B},
number = 47,
volume = 75,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}