Magnetic behavior of Y2 Fe14-x Tx B Compounds, where T = Al, Ti, V, Cr, Mn, Co, or Ni.

Abdelaal, Mervat,

Abstract


Magnetic behavior of Y2 Fe14-x Tx B Compounds, where T = Al, Ti, V, Cr, Mn, Co, or Ni.
M. M. Abd-El Aal,
Physics Department, Faculty of Women, Ain Shams University, Cairo, Egypt.

The composition and temperature dependence of the Curie temperature, saturation magnetization , anisotropy field and anisotropy constant have been studied for Y2 Fe14-x Tx B compounds with x up to 0.1 for Ti, x = 4 for T = Al, V, Mn and Cr and = 5.0 for T = Co and Ni. Decreases in both the cell volume and the saturation magnetization (Ms) except for low cobalt content are observed. The decrease is larger in the direction Ni, Al, V, Mn and Cr. The composition dependence of Ms is described by a simple dilution model when T = Ti, Al and Ni. Dramatic reductions in TC and Ms when T = V, Cr or Mn are attributed to the preference of T ions in the sublattice. For the host crystal Y2 Fe14 B, Invar-type anomalies have been found in the temperature dependences of the lattice parameter a and the unit cell volume. The magnetostriction, which is due only to the iron sublattice, is essentialy of volume character. Anisotropy fields (Ha) and anisotropy constants (K1) are strongly modified by the composition due to the site preference of the transition metal ions in the sublattice. The K1 dependences on temperature are explained in terms of competing contributions to the anisotropy from the inequivalent Fe sites. Despite the different T, the minimum room-temperature anisotropy field corresponds to ccompounds with the same number of electrons/ atom n. A more localized picture is needed to explain the 3d magnetism for T substituents which decrease n than that required for T substituents which increase n.


Other data

Title Magnetic behavior of Y2 Fe14-x Tx B Compounds, where T = Al, Ti, V, Cr, Mn, Co, or Ni.
Authors Abdelaal, Mervat 
Issue Date 1994
Journal Journal of Magnetism and Magnetic Materials 131 (1994) 148- 156 
URI http://research.asu.edu.eg/handle/123456789/167893

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