A comprehensive transport investigations on the systems exhibiting the giant magnetoresistance

(1)To为了研究磁性多层膜中自旋玻璃化转变与层间耦合的竞争，我们测量了Cu（Mm）/Co多层膜的磁化强度、磁电阻、霍尔效应和热电势。我们发现了竞争的明显证据，如饱和场的增加。最突出的特征是发现在样品与Cu（Mn）layr厚度接近15 A，我们预计在与纯Cu layrs样品的铁磁耦合。在室温下，这种耦合是铁磁的，而在70 K以下，反铁磁分量大大增加，这一结果可以部分地理解为自旋玻璃化转变和层间耦合的共同作用。(2)我们曾报道过，在反常霍尔电阻率中出现了传导电子散射几率的大的场依赖性。然而，它还没有解决。为了证实这一点，我们对表现出明显磁共振振荡的CO（Fe）/Cu多层膜进行了霍尔效应和磁共振的同时测量。我们发现了一个明显的反常霍尔系数振荡与MR振荡同步。我们还发现了热电功率的同步振荡。(3)测量了两种典型的颗粒合金体系Co-Ag和Co-Cu的霍尔效应、热电势和热导率随场的变化关系，发现它们都表现出与巨磁电阻效应相关的场依赖性。我们推测，颗粒合金中巨磁电阻效应的基本机制与多层合金中的相同。(4)我们已经研究了UNiGa的各种输运性质的场依赖性，这表明了一个大的MR效应进行讨论的磁性多层膜。我们还发现了大磁场效应在所有的测量性能。从霍尔效应和热电势，我们判断费米面在自旋重取向跃迁中发生了变化。

(1)To investigate how the spin-glass transition compete with the interlayr coupling in magnetic multilayrs, we have measured the magnetization, magnetoresistance (MR), Hall effect and thermoelectric power of Cu (Mm) /Co multilayrs. We found a clear evidence of the competition such as an increment of the saturation field. Most prominent feature was found on the sample with Cu (Mn) layr thickness near 15A where we expect a ferromagnetic coupling as in the sample with pure Cu layrs. The coupling was ferromagnetic at room temeprature, however, an antiferromagnetic component grew enormously below 70K.The result can be understood partially as due to the combined effect of the spin-glass transition and the interlayr coupling. (2) We previously reported that the large field dependence of scattering probability of conduction electron appeared in the anomalous Hall resistivity. However, it is not settled yet. In order to make sure the fact, we made simultaneous measurements of the Hall effect and MR on CO (Fe) /Cu multilayrs which exhibits the MR oscillation most clearly. We found a clear oscillation of anomalous Hall coefficient synchronized with the MR oscillation. We also found a synchronized oscillation in the thermoelectric power. (3) We measured the field dependence of the Hall effect, thermoelectric power and thermal conductivity on the two typical granular alloy system Co-Ag and Co-Cu, and found all the properties exhibit the field dependence correlated with the giant MR effect. We inferred that the basic mechanism of the giant MR effect in the granular alloys is same as that in multilayrs. (4) We have investigated the field dependence of various transport properties on UNiGa which shows a large MR effect to be discussed in relation to the magnetic multilayrs. We also found the large magnetic field effect in all the measured properties. From the Hall effect and thermoelectric power, we judged that the Fermi surface changes in the spin reorientation transition.