Condensed Matter Physics

Progress in Solid State Chemistry, 2011

Heusler compounds are a remarkable class of intermetallic materials with 1:1:1 (often called Half-Heusler) or 2:1:1 composition comprising more than 1500 members. Today, more than a century after their discovery by Fritz Heusler, they are still a field of active research. New properties and potential fields of applications emerge constantly; the prediction of topological insulators is the most recent example. Surprisingly, the properties of many Heusler compounds can easily be predicted by the valence electron count. Their extremely flexible electronic structure offers a toolbox which allows the realization of demanded but apparently contradictory functionalities within one ternary compound. Devices based on multifunctional properties, i.e. the combination of two or more functions such as superconductivity and topological edge states will revolutionize technological applications. The subgroup of more than 250 semiconductors is of high relevance for the development of novel materials for energy technologies. Their band gaps can readily be tuned from zero to z4 eV by changing the chemical composition. Thus, great interest has been attracted in the fields of thermoelectrics and solar cell research. The wide range of their multifunctional properties is also reflected in extraordinary magneto-optical, magnetoelectronic, and magnetocaloric properties. The most prominent example is the combination of magnetism and exceptional transport properties in spintronic devices. To take advantage of the extremely high potential of Heusler compounds simple rules for the understanding of the structure, the electronic structure and the relation to the properties are reviewed.

Preface Material Science has become a very important subject as an interdisciplinary course in almost all universities. Keeping this in view we have developed the subject matter for B.E. (Material Science and Metallurgy/Production Engineering/Mechanical Engineering), A.M.I.E., Diploma in engineering, M.Sc. (Material Science/Physics/Chemistry) and B.Sc. (Hons.) courses as per their latest syllabii. The book is also useful for UPSC, GATE, NET, SLET and other entrance examinations.

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this gives basic understanding of nano technology

Fundamentals of Solid State Engineering Manijeh Razeghi Fourth Edition

The effects on electronic structure properties by Co substitution in Fe 2 VAl Heusler alloy have been determined by means of first principle calculations using generalized gradient approximation and calculated equilibrium lattice constants and magnetic moments for the series Fe 2Àx Co x VAl. The value of formation energy is minimized at the Fe (A, C) sites when Co substitutes at Fe, V and Al sites. The semi metallic behavior of Fe 2 VAl fades, while spin polarization is induced on Fe replaced by Co atom due to the influence of valence electrons of Co at the Fermi level. An enhancement of the total magnetic moment on increase in the Co content is observed due to the ferromagnetic coupling of Fe and Co atoms with V atoms at the B site and hybridization between Co-Co atoms at the A/C sites.