Lee Doh C, Ghezelbash Ali, Stowell Cynthia A, Korgel Brian A
Department of Chemical Engineering, Texas Materials Institute, and Center for Nano- and Molecular Science and Technology, The University of Texas at Austin, 78712, USA.
J Phys Chem B. 2006 Oct 26;110(42):20906-11. doi: 10.1021/jp064050n.
The colloidal synthesis and magnetic properties of MnPt(3) nanocrystals are reported. The nanocrystal size depended on the Mn reactant used, but the Mn:Pt stoichiometry was always 1:3. As synthesized, the nanocrystals are compositionally disordered with the face-centered cubic (fcc) A1 phase. Annealing at 580 degrees C changed the MnPt(3) crystal structure to the compositionally ordered L1(2) phase (AuCu(3) structure) with higher magnetocrystalline anisotropy. Magnetization measurements showed that the A1 nanocrystals are paramagnetic and the L1(2) MnPt(3) nanocrystals are superparamagnetic.
报道了MnPt₃纳米晶体的胶体合成及其磁性能。纳米晶体的尺寸取决于所使用的锰反应物，但锰与铂的化学计量比始终为1:3。合成后的纳米晶体在面心立方（fcc）A1相中成分无序。在580℃退火后，MnPt₃晶体结构转变为成分有序的L1₂相（AuCu₃结构），具有更高的磁晶各向异性。磁化测量表明，A1纳米晶体是顺磁性的，而L1₂ MnPt₃纳米晶体是超顺磁性的。
