Pressure induced state in the orthorhombic (Mn1−xCox)2P system

• Published in: Journal of physics. Condensed matter Vol. 20; no. 19; pp. 195207 - 195207 (7)
• Main Authors: Zach, R, Fukami, Y, Toboła, J, Ono, F, Fruchart, D
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 14.05.2008; Institute of Physics; IOP Publishing [1989-....]
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electron density of states and band structure of crystalline solids; Electron states; Exact sciences and technology; Magnetic phase boundaries (including magnetic transitions, metamagnetism, etc.); Magnetic properties and materials; Magnetically ordered materials: other intrinsic properties; Other inorganic compounds; Physics; Band structure; Local magnetic moment; Electronic structure; Pressure effects; Cobalt Manganese Phosphides Mixed; CPA calculations; Orthorhombic lattices; Ferromagnetic-antiferromagnetic transitions; KKR calculations; Electronic density of states; Magnetic transitions; Magnetic susceptibility; PIEnergie
• ISSN: 0953-8984; 1361-648X
• DOI: 10.1088/0953-8984/20/19/195207

In this paper we present the results of ac susceptibility measurements of a (Mn0.65Co0.35)2P sample under pressure up to 7.5 GPa. The pressure induced low temperature ferromagnetic state in pressures above 5-6 GPa was established. Theoretical analysis of the electronic band structure 'under pressure' was carried out by the Korringa-Kohn-Rostoker method incorporating the coherent potential approximation (KKR-CPA). We could conclude that the local magnetic moment decreases with pressure. Moreover, when external pressure is applied along the c-axis, in the case of manganese atoms placed at the tetrahedral site, the magnetic moment practically disappears, but in the case of Co decreases only slightly. This type of behavior may be responsible for the pressure induced phase transition from the antiferromagnetic (AF) state to the ferromagnetic (F) state. KKR-CPA electronic band structure calculations undertaken in the antiferromagnetic state are also presented from which it was found that the density of states (DOS) at the Fermi level varies with applied pressure in the opposite way, when accounting for F and AF states. The rapid decrease of DOS at EF in the ferromagnetic (Mn0.65Co0.35)2P additionally supports the experimentally observed pressure induced AF-F transition.