Theoretical study of structural stability and magnetism in the Pd3Mn antiphase

Relative stability of L1(2), D0(22) and D0(23) structures as well as magnet ic properties are studied in the Pd3Mn antiferromagnet using the Korringa-K ohn-Rostoker band structure calculations within the local-spin-density appr oach, The D0(23) phase of Pd3Mn is found to be the most stable from the tot al energy analysis if accounting for the spin-polarisation. The equilibrium lattice constant in D0(23) lies between a(eq) of the L1(2) and D0(22) phas es, being about 1% larger than the experimental value. Noteworthy, the tota l energies of the ferromagnetic D0(22) and D0(23) phases of Pd3Mn markedly approach, when going down to the experimental lattice constant. In ferromag netic state of Pd3Mn the following magnetic moments (in mu (B)) 4.08, 0.12, 0.16 and 0.15 are computed on Mn and 4c, 4d and 4e sites of Pd, respective ly. In antiferromagnetic state, albeit no magnetic moment on Pd (4d), the K KR values are close to thr ferromagnetic results namely (in mu (B)) 3.99 on Mn, 0.18 on Pd (4c) and 0.16 on Pd (4e). The electronic structure and magn etic properties of Pd3V and Pd(3)Fein the L1(2), D0(22) phases are also rep orted. Tile KKR calculations show that the ground state of Pd3V is either m agnetic (L1(2)) or non-magnetic (D0(32)). Conversely, Pd3Fe exhibits ferrom agnetic properties in both crystal structures with tile Fe and Pd magnetic moments (in mu (B)) 3.28, 0.29 and 3.22, 0.22, 0.26 in L1(2) and D0(22), re spectively. Both structural and magnetic properties derived from the band s tructure KKR calculations generally correspond well to the experimental dat a. (C) 2001 Elsevier science B.V. Ail rights reserved.