Sb (0 ≤ x ≤ 0.5)*

Magnetic materials with a half-metallic band structure are desired for spin-transport-based devices. MnPtSb is one such material predicted to exhibit nearly half-metallic band structure. Our first principle calculations show that this material undergoes a half-metallic transition in Mn-rich Mn_1+xPt_1-xSb compounds at x = 0.25. Further increase of Mn content makes half-metallicity even more pronounced, as Fermi level moves well inside the minority-spin band gap, accompanied by a reduction of the unit cell volume. We have synthesized Mn_1+xPt_1-xSb (0 ≤ x < 0.5 ) compounds in cubic crystal structure using arc melting and vacuum annealing. All samples show ferrimagnetic order (in agreement with computational results) at room temperature with the Curie temperature of about 500 K. In this presentation, we will discuss the results from our theoretical and experimental investigations including electronic band structure, structural and magnetic properties of Mn_1+xPt_1-xSb compounds.