Physical property of two components nono-crystals prepared with GDM

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In this research project, nano-crystals composed of multi-elements were investigated. 2 different techniques, which are modified from Gas condensation and Deposition Method (GDM), were tested to realize 2 components nano-crystals. Additionally, basic properties of single element nanocrystals produced by the simple GDM are also reported.As basics of the multi-element nano-crystal system, magnetism of GDM Ni nano-crystals was investigated. As deposited films were composed of fine particles with approximately 9 nm in diameter. Thermal annealing up to 400°C increased the grain size of around 20 nm. Coercive forces of the nano-crystals vary in accordance with the - 6 powers of grain size smaller than 13nm. This is explained by the Random Anisotropy Model. Effective local magnetic anisotropy is deduced to be 1.9-3.5 x 104 J/ m3 and this magnitude is 2-5 times larger than that of bulk Ni. From the field cool magnetization measurement, Hc shift due to exchange anisotropy was not observed. The … More antiferromagnetic layer around grains originated from oxidation seems not to be responsible for the anisotropy.Two components nano-crystals including ferromagnetic metals such as Fe and Co were fabricated by mixing ultrafine particle flows from two individual sources. In the case where fine particles were mixed on a substrate, the composition was modulated in a large scale and this means flows do not mix well in this way. Next, we mixed the flows in the transfer tube and the modulation was improved, however, clear separation of the elements was found in an each trace of a mixed beam. Another technique modifying GDM, where fine particles were mixed with other sputtered metals on the substrate, has been tested to realize granular materials. By this way the mixing was remarkably improved compared with former ways. GMR was expected in a case of Co-Ag system, however only small magneto-resistance was found. This may be attributed to the size of Co particles and further investigation is planned. Less