Controlled synthesis of MnP nanorods:: Effect of shape anisotropy on magnetization
Controlled synthesis of MnP nanorods:: Effect of shape anisotropy on magnetization
复制标题
DOI：
10.1021/cm052080h
复制
发表时间：
2006-02-21
影响因子：
8.6
通讯作者：
Brock, SL
中科院分区：
文献类型：
--
作者：
Gregg, KA;Pererá, SC;Brock, SL
磷化锰（MnP）纳米棒的制备是通过将Mn-2-（CO）溶解在十八烯中高温注入到热的（350 ℃）三辛基氧化膦（TOPO）和三辛基膦（TOP）的表面活性剂混合物中。加热1小时后，产生沿正交MnP的B轴沿着生长的均匀短棒（20.3 +/-3.6 nm × 5.2 +/-0.89 nm）。棒是铁磁性的，在10 K和250.4 K在500 Oe的阻断温度的矫顽场为4200 Oe，并表现出只有弱的粒子间相互作用。具有长径比超过30的较长棒的样品可以通过使用较长的加热时间或多次注射来制备。在延长加热方案的情况下，还观察到立方体和较厚棒的演变。令人惊讶的是，将形状各向异性引入到MnP的纳米颗粒中对磁性能几乎没有影响，这表明固有的磁晶各向异性是主要影响。
Manganese phosphide (MnP) nanorods have been prepared by high-temperature injection of Mn-2-(CO) to dissolved in octadecene into a hot (350 degrees C) surfactant mixture of trioctylphosphine oxide (TOPO) and trioctylphosphine (TOP). Uniform short rods (20.3 +/- 3.6 nm x 5.2 +/- 0.89 nm), grown along the b axis of orthorhombic MnP, were produced after 1 h of heating. The rods were ferromagnetic, with a coercive field of 4200 Oe at 10 K and a blocking temperature of 250.4 K at 500 Oe, and exhibited only weak interparticle interactions. Samples with longer rods having an aspect ratio of over 30 can be prepared by using longer heating times or multiple injections. The evolution of cubes and thicker rods was also observed with extended heating regimens. Surprisingly, the introduction of shape anisotropy into nanoparticles of MnP has little or no influence on the magnetic properties, suggesting that the inherent magnetocrystalline anisotropy is the dominating influence.