Very Low-Temperature Magnetization Measurements on the Electron Systems with Low Characteristic Temperature

低特征温度电子系统的极低温磁化测量

基本信息

批准号：
09304038
负责人：
SAKAKIBARA Toshiro
金额：
$ 12.99万
依托单位：
HOKKAIDO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1999
项目状态：
已结题

项目摘要

Effect of magnetic field on the AFQ phase in the cubic compound PrPb3 has been studied by means of magnetization and specific heat measurements. It is found that the AFQ transition temperature TQ (=0.4〜K at H=0) remarkably increases in magnetic field. This behavior is well explained by antiferromagnetic (AF) interactions between the field-induced staggered magnetic moment in the AFQ phase. Analysis of the observed anisotropy TQ(H//[100]>TQ(H//[110]), however, strongly suggests the presence of a weak ferro-octupolar interaction.Magnetic properties of the phase IV in Ce0.75La0.25B6 have been studied under uniaxial pressure of 0.lGPa applied parallel to the [110] direction. The magnetic susceptibility of phase IV, which is isotropic at zero pressure, becomes remarkably anisotropic under the uniaxial pressure. Magnetic state of phase IV is found to be quite sensitive to the uniaxial strain.In TmTe, magnetic susceptibility increases enormously on cooling and appears to diverge upon an AF transition at TN=0.22〜K. The results imply that a ferromagnetic moment is induced in the AF phase by an alternating anisotropy due to the preexisting AFQ order at TQ=1.8〜K. This is possible when both AF and AFQ states are described by the same wave vector, in agreement with recent neutron diffraction studies.Paramagnetic effect in the superconducting mixed state of URu2Si2 has been studied. It is found that the G-L parameter κ2 decreases on cooling below Tc, suggesting that the pairing is a singlet. A d-wave superconductivity is considered to be realized in this system.The peak effect in CeRu2 has been studied by means of magnetization measurement. No trace of a first order transition nor any evidence of a paramagnetic effect is observed in the magnetization curves of the mixed state, rejecting a possibility of a phase transition to the FFLO state. The peak effect in this system is rather well explained by a synchronization effect.

磁场对立方复合PRPB3中AFQ相的影响已经通过磁化和特定的热量测量进行了研究。发现AFQ过渡温度TQ（H = 0时= 0.4〜k）在磁场中明显增加。这种行为通过在AFQ相中磁引起的交错磁矩之间的抗磁磁性（AF）相互作用很好地解释了这种行为。然而，对观察到的各向异性TQ（H // [100]> TQ（H // [110]）的分析强烈表明存在弱铁 - 八十二粒极性相互作用。在单十二级启发下，ce0.75LA0.25B6中IV期的磁性特性是在单十二次启发下的策略。在零压力下是各向同性的，在单次压力下，磁性状态对单轴应变非常敏感。在TMTE中，磁敏感性在冷却时大大增加，并且在TN = 0.22 〜K时似乎会在AF型中差异。当AF和AFQ状态与最近的中子衍射研究一致时，TQ = 1.8〜K处的AFQ顺序是可能的。 D-WAVE超导性被认为是在该系统中实现的。CERU2中的峰值效应已通过磁化测量进行了研究。在混合状态的磁化曲线中没有观察到一阶转变的痕迹，也没有任何证据表明具有顺磁性效应的迹象，从而拒绝了向FFLO状态过渡的可能性。该系统的峰值效应通过同步效应很好地解释了。