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 .

Low-temperature specific heat of CaRu1−xMnxO3 was measured to clarify the role of d electrons in ferromagnetic and antiferromagnetic orders observed above x = 0.2. Specific heat divided by temperature Cp/T is found to roughly follow a T 2 function, and relatively large magnitudes of electronic specific heat coefficient γ were obtained in wide x range. In particular, γ is unchanged from the value at x = 0 (84 mJ/K 2 mol) in the paramagnetic state for x ≤ 0.1, but linearly reduced with increasing x above x = 0.2. These features of γ strongly suggest that itinerant d electrons are tightly coupled with the evolution of magnetic orders in small and intermediate Mn concentrations.

Low-temperature magnetic and electronic properties of Sr 1−x La x RuO 3 for x ≤ 0.4 have been investigated by means of ac susceptibility χ and specific heat C p measurements to clarify the relationship between these properties and suppression of ferromagnetic (FM) order. A clear divergence associated with the FM transition is observed in the temperature variations of χ for x = 0. It changes into broad peaks by doping La, and the FM transition temperature is reduced from 161 K (x = 0) to 8.4 K (x = 0.4). Furthermore, peak-top temperature and magnitude of the peak in χ are found to significantly vary by the frequency of applied ac fields for x ∼ 0.4. Specific heat divided by temperature C p /T roughly follows a T 2 function at low temperatures for all the x range presently investigated, and substituting La for Sr increases the electronic specific heat coefficient γ from 30 mJ/K 2 mol (x = 0) to 85 mJ/K 2 mol (x = 0.4). We suggest from these results that the spatially inhomogeneous clusters of the spin-polarized Ru 4d electrons evolve as the long-range FM order breaks down, although the Ru 4d electrons still have itinerant nature.

A Zn-Al eutectoid alloy known as a fine-grained superplastic material is tested both in tension and compression under superplastic conditions, and the influence of the stress state on superplastic deformation behavior, such as flow stress, is investigated. In the compression test, deformation is interrupted and turning is performed to remove a barreled portion so that the gauge section becomes uniform, and then the deformation is continued. Microstructural change during the deformation is also investigated. As a result, flow stress in the compression becomes higher than that in tension even after the barreled portion is removed. After deformation, grain growth is observed both in the tension and compression, and growth rate in the compression is larger than in the tension.

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