Synthesis and magnetic characterization of co-axial Ge1-xMnx/a-Si heterostructures

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TY  - JOUR
  - Barth, S.; Kazakova, O.; Estrade, S.; Hobbs, R. G.; Peiro, F.; Morris, M. A.; Holmes. J. D.
  - 2011
  - December
  - Crystal Growth and Design
  - Synthesis and magnetic characterization of co-axial Ge1-xMnx/a-Si heterostructures
  - Published
  - ()
  - 11
  - 5253
  - 5259
  - A method for synthesizing Ge1xMnx/a-Si core-shell nanowires (x = 0.3(1)1.0(2)) using a supercritical fluid deposition technique, with a homogeneous distribution of manganese along the entire lengths of the crystalline Ge cores but not in the a-Si shells, is reported. Investigations into the magnetic properties of the heterostructured nanowires revealed a significant influence of the amorphous Si shell covering the surface of the core Ge0.997Mn0.003 nanowires compared to pristine Ge0.997Mn0.003 nanowires with no a-Si coating. The magnetic data revealed diminished values of both the remanence and the saturation magnetization for pristine Mn-doped Ge nanowires at higher temperatures when compared to the Ge1xMnx/a-Si coreshell nanowires, whereas both parameters increased as the temperature dropped down to 5 K. Differences in the temperature-dependent evolution of the coercivity were observed in the magnetically harder core-shell nanowires compared to the pristine Ge0.997Mn0.003 nanowires, showing a drop of 26% at 5 K vs roomtemperature compared to a drop of 66% for the pristine nanowires. The low dopant concentration (0.3(1)%) of Mn in the core-shell nanowires, combined with the observed ferromagnetic properties, suggests a combination of hole-mediated exchange and confinement processes are responsible for the observed properties. Our observations show the importance of a protective layer in covering the oxidation-sensitive dilute magnetic semiconductor nanowires.
  - http://pubs.acs.org/journal/cgdefu
DA  - 2011/12
ER  - 
@article{V117321829,
   = {Barth, S. and  Kazakova, O. and  Estrade, S. and  Hobbs, R. G. and  Peiro, F. and  Morris, M. A. and  Holmes. J. D.},
   = {2011},
   = {December},
   = {Crystal Growth and Design},
   = {Synthesis and magnetic characterization of co-axial Ge1-xMnx/a-Si heterostructures},
   = {Published},
   = {()},
   = {11},
  pages = {5253--5259},
   = {{A method for synthesizing Ge1xMnx/a-Si core-shell nanowires (x = 0.3(1)1.0(2)) using a supercritical fluid deposition technique, with a homogeneous distribution of manganese along the entire lengths of the crystalline Ge cores but not in the a-Si shells, is reported. Investigations into the magnetic properties of the heterostructured nanowires revealed a significant influence of the amorphous Si shell covering the surface of the core Ge0.997Mn0.003 nanowires compared to pristine Ge0.997Mn0.003 nanowires with no a-Si coating. The magnetic data revealed diminished values of both the remanence and the saturation magnetization for pristine Mn-doped Ge nanowires at higher temperatures when compared to the Ge1xMnx/a-Si coreshell nanowires, whereas both parameters increased as the temperature dropped down to 5 K. Differences in the temperature-dependent evolution of the coercivity were observed in the magnetically harder core-shell nanowires compared to the pristine Ge0.997Mn0.003 nanowires, showing a drop of 26% at 5 K vs roomtemperature compared to a drop of 66% for the pristine nanowires. The low dopant concentration (0.3(1)%) of Mn in the core-shell nanowires, combined with the observed ferromagnetic properties, suggests a combination of hole-mediated exchange and confinement processes are responsible for the observed properties. Our observations show the importance of a protective layer in covering the oxidation-sensitive dilute magnetic semiconductor nanowires.}},
   = {http://pubs.acs.org/journal/cgdefu},
  source = {IRIS}
}
AUTHORSBarth, S.; Kazakova, O.; Estrade, S.; Hobbs, R. G.; Peiro, F.; Morris, M. A.; Holmes. J. D.
YEAR2011
MONTHDecember
JOURNAL_CODECrystal Growth and Design
TITLESynthesis and magnetic characterization of co-axial Ge1-xMnx/a-Si heterostructures
STATUSPublished
TIMES_CITED()
SEARCH_KEYWORD
VOLUME11
ISSUE
START_PAGE5253
END_PAGE5259
ABSTRACTA method for synthesizing Ge1xMnx/a-Si core-shell nanowires (x = 0.3(1)1.0(2)) using a supercritical fluid deposition technique, with a homogeneous distribution of manganese along the entire lengths of the crystalline Ge cores but not in the a-Si shells, is reported. Investigations into the magnetic properties of the heterostructured nanowires revealed a significant influence of the amorphous Si shell covering the surface of the core Ge0.997Mn0.003 nanowires compared to pristine Ge0.997Mn0.003 nanowires with no a-Si coating. The magnetic data revealed diminished values of both the remanence and the saturation magnetization for pristine Mn-doped Ge nanowires at higher temperatures when compared to the Ge1xMnx/a-Si coreshell nanowires, whereas both parameters increased as the temperature dropped down to 5 K. Differences in the temperature-dependent evolution of the coercivity were observed in the magnetically harder core-shell nanowires compared to the pristine Ge0.997Mn0.003 nanowires, showing a drop of 26% at 5 K vs roomtemperature compared to a drop of 66% for the pristine nanowires. The low dopant concentration (0.3(1)%) of Mn in the core-shell nanowires, combined with the observed ferromagnetic properties, suggests a combination of hole-mediated exchange and confinement processes are responsible for the observed properties. Our observations show the importance of a protective layer in covering the oxidation-sensitive dilute magnetic semiconductor nanowires.
PUBLISHER_LOCATION
ISBN_ISSN
EDITION
URLhttp://pubs.acs.org/journal/cgdefu
DOI_LINK
FUNDING_BODY
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