Study on Unconventional Superconductivity and Magnetism in Heavy Fermion Superconductors by Means of Direct Measurements of Anisotropy

（I） Anisotropic Peak Effect in CeRu D22Detailed magnetization measurements of CeRu D22single crystals with different purity are performed at very low temperatures in order to clarify whether their peak effect are due to the Fulde-Ferrell-Larkin-Chinnikov（F性） transition。从山顶到下田野一侧的一个固定的田野，作为一个例子变得有影响。对Ginzburg-Landau （G-L）参数的无节制，ky-D22 y-D2继续从Ty-D2cy-D2冷却，指示超级条件的小paramagnetic抑制。这些结果与FFLO过渡的场景不一致。（ii） Unconventional Superconductivity in Uru·D22·D2Si·D2Magnetization and specific heat measurements have been performed on a high-quality single cr\of heavy fermion superconductor Uru·D22·D2·D Temperature dependences of the G-L parameters，D21，D2和D22， together with those of upper critical field H2c2，thermodynamic critical field H2c2， were obtained from the above measurements。G-L参数decrease both for H//c and for H//a with decreasing temperature from 1.1 K while in the temperature range between 1.1 K and T-D2c的G-L参数slightly increase for H//a as temperature decreases。Temperature dependence of H-D2c-D2 is similar to that of conventional superconductors。These result suggest the presence of the paramagnetic suppression of the superconductivity at least in the low temperature region， consistent with the strong suppression of HイD2c2エD2 at low temperOracle。（iii） Anisotropy of the Superconductivity in UPdイD22イD2AlイD23イD2 was investigated by means of magnetization measurements。您的位置：知道173>> thermodynamic c\field H\D2c\D2 was found to be 6 x10\D12\D1 Oe。

(I) Anisotropic Peak Effect in CeRuィイD22ィエD2Detailed magnetization measurements of CeRuィイD22ィエD2 single crystals with different purity are performed at very low temperatures in order to clarify whether their peak effects are due to the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) transition. The onset field of the peak shifts to lower field side as the sample becomes impure. Regardless of the purity the Ginzburg-Landau (G-L) parameter, κィイD22ィエD2 continues to increase on cooling from TィイD2cィエD2, indicating little paramagnetic suppression of the superconductivity. These results disagree with the scenario of the FFLO transition.(ii) Unconventional Superconductivity in UruィイD22ィエD2SiィイD22ィエD2Magnetization and specific heat measurements have been performed on a high-quality single crystal of heavy fermion superconductor UruィイD22ィエD2SiィイD22ィエD2. Temperature dependences of the G-L parameters κィイD21ィエD2 and κィイD22ィエD2, together with those of upper critical field HィイD2c2ィエD2 and thermodynamic critical field HィイD2cィエD2, were obtained from the above measurements. The G-L parameters decrease both for H//c and for H//a with decreasing temperature from 1.1 K while in the temperature range between 1.1 K and TィイD2cィエD2 the G-L parameters slightly increase for H//a as temperature decreases. Temperature dependence of HィイD2cィエD2 is similar to that of conventional superconductors. These results suggest the presence of the paramagnetic suppression of the superconductivity at least in the low temperature region, consistent with the strong suppression of HィイD2c2ィエD2 at low temperatures.(iii) Anisotropy of the Superconductivity in UPdィイD22ィエD2AlィイD23ィエD2 was investigated by means of magnetization measurements. The thermodynamic critical field HィイD2cィエD2 was found to be 6x10ィイD12ィエD1 Oe.