The magnetic and electronic properties of Sr 1−x La x RuO 3 were studied by means of dc-magnetization, acsusceptibility, specific heat, and electrical resistivity measurements. The dc-magnetization and ac-susceptibility measurements have revealed that the transition temperature and the ordered moment of the ferromagnetic order are strongly suppressed as La is substituted for Sr. The ac-susceptibility exhibits a peak at T * due to the occurrence of spontaneous spin polarization. Furthermore, we observed that T * shows clear frequency variations for x ≥ 0.3. The magnitude of the frequency shifts of T * is comparable to that of cluster-glass systems, and the frequency dependence is well described in terms of the Vogel-Fulcher law. On the other hand, it is found that the linear specific heat coefficient γ enhances with the suppression of the ferromagnetic order. The relatively large γ values reflect the presence of the Ru 4d state at Fermi level, and hence, the magnetism of this system is considered to be tightly coupled with the itinerant characteristics of the Ru 4d electrons. The present experimental results and analyses suggest that the intrinsic coexistence of the spatially inhomogeneous magnetic state and the itinerant nature of the Ru 4d electrons is realized in this system, and such a feature may be commonly involved in La-and Ca-doped SrRuO 3 .

We have succeeded in growing single crystals of the heavy-fermion superconductor CeCo(In 1−x Zn x ) 5 with x ≤ 0.07. Measurements of specific heat, electrical resistivity, dc magnetization and ac susceptibility revealed that the superconducting (SC) transition temperature T c decreases from 2.25 K (x = 0) to 1.8 K (x = 0.05) by doping Zn into CeCoIn 5 . Furthermore, these measurements indicate a development of a new ordered phase below T o ∼ 2.2 K for x ≥ 0.05, characterized by the reduced magnetization and electrical resistivity in the ordered phase, and the enhancement of specific heat at T o . This phase transition can be also recognized by the shoulder-like anomaly seen at H o ∼ 55 kOe in the field variations of the magnetization at low temperatures, which is clearly distinguished from the superconducting critical fields H c2 = 49 kOe for x = 0.05 and 42 kOe for x = 0.07. We suggest from these results that the antiferromagnetic (AFM) order is generated by doping Zn, and the interplay between the SC and AFM orders is realized in CeCo(In 1−x Zn x ) 5 .The nature of unusually enhanced fluctuations and ordered states related to the quantum critical phenomena has been attracting much interest in the physics of the heavy-fermion systems. These features are observed in the vicinity of the quantum critical point (QCP), corresponding to the phase transition at zero temperature, which is generated by suppressing the magnetically ordered state via applying pressure, magnetic field and doping ions. Near the QCP, the non-Fermiliquid (NFL) properties evolve in temperature variations of thermodynamic and transport quantities, indicating the existence of new types of low-energy excitations different from those expected in usual Fermi-liquid state. Furthermore, the unconventional superconductivity (SC) often emerges near the QCP, and it is therefore believed that the magnetic fluctuation enhanced near the QCP plays a crucial role in the formation of the Cooper pairs.Among the heavy-fermion systems showing the quantum critical phenomena, the heavy-fermion superconductor CeCoIn 5 (the HoCoGa 5 -type tetragonal structure) is one of the most intensively investigated compounds. The SC transition of CeCoIn 5 is characterized by an anomalously large specific-heat jump ∆C/γT c = 4.5 at the transition temperature T c = 2.3 K.1) A strong Pauli-limited effect gives rise to a first-order transition at the SC critical field H c2 below 0.7 K.2-4) In addition, above H c2 the NFL behavior is observed in the temperature variations of the bulk quantities, which is considered to be due to the effect of quantum critical fluctuation induced in the vicinity of antiferromagnetism. 5)In fact, an antiferromagnetic (AFM) order is generated by substituting ions for Co and In. In the mixed compounds * E-mail address: makotti@mx.ibaraki.ac.jp CeRh 1−x Co x In 5 , 6) it is revealed that substituting Rh for Co reduces T c down to ∼ 1.5 K at x ∼ 0.8, and the AFM order develops in the Co concentrations below x c ∼ 0.8. A continuous increase of the AFM trans...

We report on the anisotropic properties of Pauli-limited superconductivity (SC) and antiferromagnetism (AFM) in the solid solutions CeCo(In1−xZnx)5 (x ≤ 0.07). In CeCo(In1−xZnx)5, the SC transition temperature Tc is continuously reduced from 2.3 K (x = 0) to ∼ 1.4 K (x = 0.07) by doping Zn, and then the AFM order with the transition temperature of TN ∼ 2.2 K develops for x larger than ∼ 0.05. The present thermal, transport and magnetic measurements under magnetic field B reveal that the substitution of Zn for In yields little change of low-temperature upper critical field µ0Hc2 for both the tetragonal a and c axes, while it monotonically reduces the SC transition temperature Tc. In particular, the magnitudes of µ0Hc2 at the nominal Zn concentration of x = 0.05 (measured Zn amount of ∼ 0.019) are 11.8 T for B || a and 4.8 T for B || c, which are as large as those of pure compound though Tc is reduced to 80% of that for x = 0. We consider that this feature originates from a combination of both an enhanced AFM correlation and a reduced SC condensation energy in these alloys. It is also clarified that the AFM order differently responds to the magnetic field, depending on the field directions. For B || c, the clear anomaly due to the AFM transition is observed up to the AFM critical field of ∼ 5 T in the thermodynamic quantities, whereas it is rapidly damped with increasing B for B || a. We discuss this anisotropic response on the basis of a rich variety of the AFM modulations involved in the Ce115 compounds.

To clarify the magnetic properties of cluster-glass states in Sr 1−x La x RuO 3 (0.3 ≤ x ≤ 0.5), we report herein the results of muon spin relaxation (µSR) and neutron powder diffraction measurements. The µSR experiments showed that magnetic clusters start developing well above the peak temperature T * in the ac susceptibility. The volume fraction of the magnetically ordered region increases continuously with decreasing temperature, showing no anomaly at T * , and reaches nearly 100% at the lowest temperature. The temperature variation of the volume fraction is essentially independent of the La concentration in the x range presently investigated, although the dc magnetization is significantly suppressed with increasing x. Neutron powder diffraction experiments revealed that the ground state for x = 0.3 is a long-range ferromagnetic ordered state. These results indicate that, with decreasing temperature, cluster-glass states in Sr 1−x La x RuO 3 gradually develop into long-range ferromagnetic ordered states with decreasing temperature, and that the magnetic ordering process differs strikingly from that expected for a conventional second-order ferromagnetic transition. IntroductionIn general, the 4d orbitals in 4d transition-metal oxides are more delocalized than the 3d orbitals in 3d transition-metal oxides; therefore, a conventional band picture is considered a suitable starting point for understanding such 4d electronic states. However, 4d transition-metal oxides exhibit a variety of intriguing electronic properties, such as quantum criticality, 1, 2) non-Fermi liquid behavior, 3) and unconventional superconductivity.4) These intriguing electronic properties imply that the correlation effect of 4d electrons is important, and that the electronic states are not trivial.Although 4d transition-metal oxides rarely show magnetic ordering, SrRuO 3 exhibits ferromagnetic order below T C = 160 K, and the ordered moment is approximately 1.1 µ B .

TiO 2 thin film for the dye sensitized solar cell was deposited by the electrophoresis method using the super fine particle of TiO 2 (P-25) and the cell characteristics were evaluated. Thin films of high quality without cracks were obtained using only ion free water without binder and also using the constant current method compared with the constant voltage method. The quality of thin film increased with decreasing value of constant current and deposition time. The desired film thickness could be controlled by the deposition time. The maximum value of the open circuit voltage of a cell was about 480 mV for the electrophoresis current density of about 0.03 mA/cm 2 and deposition time of 800 s. The maximum value of the short circuit current density was about 0.4 mA/cm 2 for the electrophoresis current density of about 0.05 mA/cm 2 and deposition time of 530 s.