Minoru Sasaki

Bio: Minoru Sasaki is an academic researcher from Hiroshima University. The author has contributed to research in topics: Intercalation (chemistry) & Aqueous solution. The author has an hindex of 14, co-authored 77 publications receiving 753 citations.

Specific heat measurements of intercalation compounds M x TiS 2 (M=3 d transition metals) using ac calorimetry technique

Abstract: Specific heats of 3d transition metal intercalates of 1T-CdI2-type TiS2, M x TiS2 (M=V, Cr, Mn, Fe, Co, and Ni; 0≤x≤1), have been measured in the temperature range 1.6–300 K using an ac calorimetry technique. The electronic specific heat coefficient γ (2–100 mJ/mole K2) and the Debye temperature ϑD (240–430 K) are found to depend on the guest 3d metals and their concentrations. All the intercalates show anomalous specific heat at low temperatures following an α–δ lnT dependence (α and δ are constants), as found in dilute alloys.

Electrical Resistivity and Thermoelectric Power of Intercalation Compounds MxTiS2 (M = Mn, Fe, Co, and Ni)

Abstract: The temperature dependence of electrical resistivity and thermoelectric power of the intercalation compounds of MxTiS2 (M = Mn, Fe, Co, and Ni; 0 ≦ x ≦ 1/3) with layered structures are measured over the temperature range 1.5 to 300 K. These experimental results can be explained by a simple model, which takes into account a temperature-independent residual term and intra- and intervalley scattering by acoustic phonons. It is also shown that a phonon drag effect is effective for the thermopower. The effect of intercalation of 3d metals into TiS2 layers on the electronic properties is discussed. Die Temperaturabhangigkeit des elektrischen Widerstands und der Thermospannung der Interkalate von MxTiS2 (M = Mn, Fe, Co, und Ni; 0 ≦ x ≦ 1/3) mit Schichtstrukturen werden bei Temperaturen von 1,5 bis 300 K gemessen. Die experimentellen Ergebnisse konnen durch ein einfaches Modell erklart werden, das einen temperaturunabhangigen Restterm sowie „intra- und intervalley scattering” durch akustische Phononen berucksichtigt. Es wird auch gezeigt, das ein „phonon-drag”-Effekt fur die Thermospannung wirksam ist. Der Einflus der Interkalation von 3d-Metallen in die TiS2-Schichten auf die elektronischen Eigenschaften wird diskutiert.

Resonant levels in bulk thermoelectric semiconductors

Abstract: Distortions of the electronic density of states (DOS) are a potent mechanism to increase the thermopower of thermoelectric semiconductors, thereby increasing their power factor. We review band-structure engineering approaches that have been used to achieve this, resonant impurity levels, dilute Kondo effects, and hybridization effects in strongly correlated electron systems. These can increase the thermoelectric power of metals and semiconductors through two mechanisms: (1) the added density of states increases the thermopower in a nearly temperature-independent way; (2) resonant scattering results in a strong electron energy filtering effect that increases the thermopower at cryogenic temperatures where the electron–phonon interactions are weaker. Electronic structure calculation results for Tl:PbTe and Ti:PbTe are contrasted and identify the origin of the thermopower enhancement in Tl:PbTe. This leads to a discussion of the conditions for DOS distortions to produce thermopower enhancements and illustrates the existence of an optimal degree of delocalization of the impurity states. The experimentally observed resonant levels in several III–V, II–VI, IV–VI and V2-VI3 compound semiconductor systems are reviewed.

The Environmental Chemistry of Aluminum

Abstract: The Quantitation of Aqueous Aluminum, P.R. Bloom and M.S. Erich Aqueous Equilibrium Data for Mononuclear Aluminum Species, D.K. Nordstrom and H.M. May Inorganic Aluminum Bearing Solid Phases, B.S. Hemingway and G. Sposito Aqueous Polynuclear Aluminum Species, P.M. Bertsch and D.R. Parker Environmental Chemistry of Aluminum-Organic Complexes, G.F. Vance, F.J. Stevenson, and F.J. Sikora Surface Reactions of Aqueous Aluminum Species, P.M. Jardine and L.W. Zelazny The Surface Chemistry of Aluminum Oxides and Hydroxides, S.R. Goldberg, J.A. Davis, and J.D. Hem The Solubility of Aluminum in Soils, W.L. Lindsay and P.M. Walthall The Chemistry of Aluminum in Surface Waters, C.T. Driscoll and K.M. Postek Aluminum Geochemistry at the Catchment Scale in Watersheds Influenced by Acidic Precipitation, W.H. Hendershot, F. Courchesne, and D.S. Jeffries Index