Tuning the bimetallic amide-imide precursor system to make paramagnetic GaMnN nanopowders
M. Drygas , J.F. Janik , M. Musiał-Karg , Jacek Gosk , A. Twardowski
AbstractA bimetallic molecular system made of gallium (III) tris(dimethyl)amide Ga(NMe2)3 and manganese (II) bis(trimethylsilyl)amide Mn[N(SiMe3)2]2 (Me = CH3, fixed initial Mn-content 10 at.%) was subjected to ammonolysis in refluxing/liquid ammonia. Upon isolation at room temperature, the amide-imide mixed metal precursor was pyrolyzed at elevated temperatures under an ammonia flow by two different routes. Route 1 consisted of a direct nitridation at high temperatures of 500, 700 or 900 °C. In route 2, a low temperature pyrolysis at 150 °C was applied prior to nitridation at the same final temperatures as in route 1. All nanopowders were characterized by XRD diffraction, FT-IR spectroscopy, and SEM/EDX microscopy and analysis. Thorough magnetization measurements in function of magnetic field and temperature were carried out with a SQUID magnetometer. In all samples, the paramagnetic phase of GaMnN was accompanied by an antiferromagnetic by-product linked to a Mn-containing species from decomposition and oxidation of Mn-precursor excess. The Mn-contents in the crystalline GaMnN, i.e., Mn-incorporated in GaN crystal lattice, were of the order of 2-3 at.% mostly independent on the nitridation route whereas the latter had a pronounced effect on amounts of the antiferromagnetic by-product. © 2016 Elsevier B.V.
|Journal series||Materials Chemistry and Physics, ISSN 0254-0584|
|Publication size in sheets||0.5|
|Keywords in English||Amides; Ammonia; Antiferromagnetism; Crystal growth; Magnetic properties; Magnetometers; Nanostructured materials; Nanostructures; Nitridation; Nitrides; Paramagnetism; Pyrolysis; Semiconducting gallium; Temperature, Antiferromagnetics; Direct nitridation; Elevated temperature; Final temperatures; Low-temperature pyrolysis; Magnetization measurements; Paramagnetic phase; SQUID magnetometers, Manganese|
|Score|| = 30.0, 28-11-2017, ArticleFromJournal|
= 35.0, 28-11-2017, ArticleFromJournal
|Publication indicators||: 2016 = 2.084 (2) - 2016=2.283 (5)|
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