Influence of the Ba2+/Sr2+ content and oxygen vacancies on the stability of cubic Ba(x)Sr(1-x)Co(0.75)Fe(0.25)O(3-δ).

We present a theoretical and experimental study on the influence of the Ba/Sr and Co/Fe ratios as well as the oxygen-non-stoichiometry on the stability of Ba0.5Sr0.5Co0.

Site-preferential design of itinerant ferromagnetic borides: experimental and theoretical investigation of MRh6B3 (M = Fe, Co).

Single-phase polycrystalline samples of the compounds MRh(6)B(3) (M = Fe, Co) as well as single crystals of CoRh(6)B(3) have been synthesized by arc-melting the elements under a purified argon atmosphere in a water-cooled copper crucible. The characterization of the new phases was achieved by using single-crystal and powder X-ray diffraction as well as EDX measurements. The two phases are isotypic and crystallize in the hexagonal Th(7)Fe(3) structure type (space group P6(3)mc, no.

A combinatorial study of inverse Heusler alloys by first-principles computational methods.

In continuation of our recent combinatorial work on 810 X(2)YZ full Heusler alloys, a computational study of the same class of materials but with the inverse (XY)XZ crystal structure has been performed on the basis of first-principles (GGA) total-energy calculations using pseudopotentials and plane waves. The predicted enthalpies of formation evidence 27 phases to be thermochemically stable against the elements and the regular X(2)YZ type. A chemical-bonding study yields an inherent tendency for structural distortion in a majority of these alloys, and we predict the existence of the new tetragonal phase Fe(2)CuGa (P4(2)/ncm; a = 5.

A combinatorial study of full Heusler alloys by first-principles computational methods.

A combinatorial scan of a total of 810 full Heusler alloys is performed on the basis of first-principles (GGA) total-energy calculations using pseudopotentials and plane waves to predict their lattice parameters and magnetic moments. About 60% of the investigated intermetallics turn out as being thermochemically stable with respect to the constituting elements. The presentation of the calculated magnetic moments in a periodic system of full Heusler phases is accomplished and yields periodic trends for the physical properties as a function of their compositions and as a function of the valence-electron concentration within a modified Slater-Pauling scheme.

The role of vacancies and local distortions in the design of new phase-change materials.

Phase-change materials are of tremendous technological importance ranging from optical data storage to electronic memories. Despite this interest, many fundamental properties of phase-change materials, such as the role of vacancies, remain poorly understood. 'GeSbTe'-based phase-change materials contain vacancy concentrations around 10% in their metastable crystalline structure.

Unusual Mn-Mn spin coupling in the polar intermetallic compounds CaMn2Sb2 and SrMn2Sb2.

Large single-crystals of two polar intermetallic phases, CaMn2Sb2 and SrMn2Sb2, have been grown using In or Sn as metal fluxes and characterized by single-crystal X-ray diffraction. The two compounds are isostructural and crystallize with the CaAl2Si2 structure (space group P3m1, No. 164) with unit cell parameters determined at 120(2) K of a = 4.