Gas Phase Synthesis of Non-Agglomerated Nanoparticles Using Coulombic Repulsive Force

发展了一种快速沉积纳米粒子薄膜的离子化化学气相沉积方法，该方法是在衬底上以高的粒子数密度广泛、均匀地沉积非团聚的纳米粒子。以正硅酸乙酯（TEOS）和三羰基亚硝酰钴（CoTN）为原料，利用自行研制的合成装置，分别合成了SiO_2和Co纳米粒子。取得了以下结果。(1)SiO_2纳米粒子（1）在40 s的沉积时间内，在14 × 14 mm ~ 2的Si衬底上均匀地沉积了直径为10 nm的未团聚的带负电荷的SiO_2粒子，粒子数密度为10 μ <10>cm <-2>~ 2。(2)用接触充电法在带正电荷的线上选择性地沉积了直径为20 nm的无团聚SiO_2颗粒。纳米颗粒线的长度、宽度和数密度为10 mm、500 nm和4 × 10 - <10>6cm-2<-2>。(2)Co纳米颗粒（1）具有14 nm直径的非团聚Co颗粒以10^ cm^2的颗粒数密度均匀地沉积<11>在<-2>20 × 20 mm ^2面积的Si衬底上（2）合成的Co纳米颗粒是铁磁性的。(3)在热氧化膜覆盖的Si衬底上形成的Co纳米颗粒膜显示出磁阻。

Ionization CVD method has been developed to form fast nanparticle films which non-agglomerated particles are deposited widely and uniformly on a substrate with a high number density. SiO_2 and Co nanoparticles have been synthesized from tetraethylorthosilicate (TEOS) and cobalt tricarbonyl nitrosyl (CoTN), respectively, by the developed synthesis apparatus. Following results have been obtained.(1) SiO_2 nanoparticles(1) Non-agglomerated and negatively charged SiO2 particles with 10 nm diameter are deposited uniformly with particle number density of 10^<10> cm^<-2> on Si substrate of 14x14 mm^2 area in the deposition time of 40 s.(2) Non-agglomerated SiO_2 particles with 20 nm diameter are deposited selectively on positively charged lines drew by the contact charging method. The length, wide, and number density of the nanoparticle lines are 10 mm, 500 nm and 4x10^<10> cm^<-2>.(2)Co nanoparticles(1) Non-agglomerated Co particles with 14 nm diameter are deposited uniformly with particle number density of 10^<11> cm^<-2> on Si substrate of 20x20 mm^2 area(2) Co nanoparticles synthesized are ferromagnetic.(3) Co nanoparticle films formed on a Si substrate coated with a thermal oxide film show a magnetic resistance.