LaNiSi: A Symmetric Mirror Homologous Series in the La-Ni-Si System.

A series of four homologous silicides have been discovered during systematic explorations in the central part of the La-Ni-Si system at 1000 °C. All compounds LaNiSi ( = 3; = 28.8686(8), = 4.

Effect of the annealing treatment on structural and transport properties of thermoelectric Sm(FeNi)4Sbthin films.

The crystallographic and transport properties of thin films fabricated by pulsed laser deposition and belonging to the Sm(FeNi)Sbfilled skutterudite system were studied with the aim to unveil the effect exerted by temperature and duration of thermal treatments on structural and thermoelectric features. The importance of annealing treatments in Ar atmosphere up to 523 K was recognized, and the thermal treatment performed at 473 K for 3 h was selected as the most effective in improving the material properties. With respect to the corresponding bulk compositions, a significant enhancement in phase purity, as well as an increase in electrical conductivity and a drop in room temperature thermal conductivity, were observed in annealed films.

Crystal and Magnetic Structures of the Ternary HoNiSi and HoNiGe Compounds: An Example of Intermetallics Crystallizing with the ZrNiP Prototype.

We report two new rare-earth (R) ternary intermetallic compounds-HoNiT with T = Si and Ge-that correspond to the RNiT phase earlier reported to form in Dy-Ni-T and Ho-Ni-T ternary systems. The compounds crystallize in a filled version of the orthorhombic ZrNiP-type structure with = 0.52; their stoichiometry, determined from both single-crystal and powder X-ray diffraction data, is centered on HoNiT with a narrow solid solubility range for the silicide, while the germanide appears to be a line phase.

Investigation on the Power Factor of Skutterudite Sm(FeNi)Sb Thin Films: Effects of Deposition and Annealing Temperature.

Filled skutterudites are currently studied as promising thermoelectric materials due to their high power factor and low thermal conductivity. The latter property, in particular, can be enhanced by adding scattering centers, such as the ones deriving from low dimensionality and the presence of interfaces. This work reports on the synthesis and characterization of thin films belonging to the Sm(FeNi)Sb-filled skutterudite system.

Stability, Crystal Chemistry, and Magnetism of UNiB and NbNiB and the Role of Uranium in the Formation of the Quaternary UNbNiB and UNbNiB Systems.

We investigated the U-Ni-B and Nb-Ni-B systems to search for possible new heavy fermion compounds and superconducting materials. The formation, crystal chemistry, and physical properties of UNiB and NbNiB [ternary derivatives of the cubic CrC-type (116, 3̅)] have been studied; the formation of the hypothetical "UNiB" and "NbNiB" has been disproved. UNiB [ = 10.

Band filling and disorder effects on the normal state thermoelectric behavior in MgB.

The goal of this work is providing a comprehensive interpretation framework for the wide and varied experimental phenomenology of the Seebeck effect in MgB samples with different levels of doping in either π or σ bands and different levels of disorder, using a combined experimental and theoretical approach. We calculate the temperature dependent diffusive Seebeck coefficient S (T) with the Boltzmann equation resolved in relaxation time approximation, taking into account the scattering with phonons and impurities, the effect of renormalization and the effect doping in a rigid band approximation. We show that selective disorder has a sizeable effect on the S magnitude, as it tunes the relative contributions of σ and π bands.

RAuPn (R = Y, Gd-Tm; Pn = Sb, Bi): A Link between CuSn and GdAg.

A new series of intermetallic compounds RAuPn (R = Y, Gd-Tm; Pn = Sb, Bi) has been discovered during the explorations of the Au-rich parts of rare-earth-containing ternary systems with p-block elements. The existence of the series is strongly restricted by both geometric and electronic factors. RAuPn compounds crystallize in the hexagonal crystal system with space group P6/m (a = 8.

Crystal Chemistry of the New Families of Interstitial Compounds R6Mg23C (R = La, Ce, Pr, Nd, Sm, or Gd) and Ce6Mg23Z (Z = C, Si, Ge, Sn, Pb, P, As, or Sb).

The crystal chemical features of the new series of compounds R6Mg23C with R = La-Sm or Gd and Ce6Mg23Z with Z = C, Si, Ge, Sn, Pb, P, As, or Sb have been studied by means of single-crystal and powder X-ray diffraction techniques. All phases crystallize with the cubic Zr6Zn23Si prototype (cF120, space group Fm3̅m, Z = 4), a filled variant of the Th6Mn23 structure. While no Th6Mn23-type binary rare earth-magnesium compound is known to exist, the addition of a third element Z (only 3 atom %), located into the octahedral cavity of the Th6Mn23 cell (Wyckoff site 4a), stabilizes this structural arrangement and makes possible the formation of the ternary R6Mg23Z compounds.

Synthesis, crystal and electronic structure of the quaternary magnetic EuTAl4Si2 (T = Rh and Ir) compounds.

Single crystals of the quaternary europium compounds EuRhAl4Si2 and EuIrAl4Si2 were synthesized by using the Al-Si binary eutectic as a flux. The structure of the two quaternary compounds has been refined by single crystal X-ray diffraction. Both compounds are stoichiometric and adopt an ordered derivative of the ternary KCu4S3 structure type (tetragonal tP8, P4/mmm).