Journal of Magnetism and Magnetic Materials 102 (1991) 297-304 North-Holland Effect of Mn and Ni on the electrical resistivity of amorphous Fe csa-x-y&,MnxB,,Si, alloys AK. Nigam ‘, Nirupama Sharma b, Shiva Prasad b, Girish Chandra ‘, S.N. Shringi b, R. Krishnan ’ and P. Rougier ’ * zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA Tata Institute of fiundamental Research, Homi Bhabha Road, Bombay 400 OOS, India h Department of Physics, Indian Institute of Technology, Powai, Bombay 400 076, India ’ Laboratoire de Magnbisme et M atkriaux M agnhiques, CNRS, 92195 Meudon, France Received 4 April 1991; in revised form 11 June 1991 Electrical resistivity studies have been carried out on a-Fe(,,_,_,, Ni,Mn,BIzSi, alloys (0 < x < 5.5; 20 < y < 50). It is found that the resistivity behavior in these alloys is different in some aspects from those that contain Cr instead of Mn. In the Cr containing alloys a T* term in the resistivity expression is found to be dominant at temperatures above T,,,, while in Mn containing alloys the dominant term has an effective power of less than 1.5. It is conjectured that in Cr containing alloys it is the simultaneous presence of a negative T”’ and a positive T2 term which leads to a second temperature minimum in resistivity at high temperature ( > 100 K). In the Mn containing alloys, however, we do not find evidence for the presence of two such terms of opposite signs. It was also found that the presence of Ni increases the positive temperature coefficient of resistivity, but the increase was stronger in Mn containing alloys. 1. Introduction The manner in which the presence of various transition metals affects the electrical and mag- netic properties of Fe based TM-M (TM = transition metal, M = metalloid) metallic glasses, has been a subject of study for quite sometime [l-27]. The main aim of these studies has been to study the effect of the presence of early 3-d TMs like Cr and V with or without the presence of Ni in Fe based alloys. As far as the magnetic proper- ties are concerned it is known that the addition of Cr or V leads to a sharp fall.in magnetic moment and Curie temperature [l-7]. In the case of elec- trical properties, it has been observed that in the absence of Ni, the addition of Cr and V leads to two minima in resistivity [g-13], one at low tem- peratures around 20 K and the other at higher temperatures (above 100 IS). In the presence of Ni, on the other hand, one observes only a single minimum but the temperature at which it is ob- served increases monotonically with the concen- tration of Cr [14,1.5]. The addition of late transi- tion metals like Ni in a-Fe-M alloys, on the other hand, does not cause changes which are as signifi- cant as in the case of early 3-d TM substitutions [2,16,17]. The addition of Mn, which is nearest to Fe in the periodic table from early 3-d TM side, shows effects which only sometimes are similar to that of Cr and V. As an example, the presence of Mn in Fe based alloys causes a reduction in the magnetic moment and Curie temperature T,, as in the case of Cr and V [5,18,19]. Its presence, however, is known to cause a small increase in the magnetic moment in Co based alloys [20-221 unlike the presence of Cr [23]. The effect of the introduction of Mn in FeNi based alloys is even more striking and is very different from Cr addi- tions. For certain concentrations of Ni and Mn in a-FeNiMnBSi alloys, a sharp increase in the mag- netic moment is observed [18,24]. These features indicate that the effect of Mn addition could be different from that of other early 3-d transition 0304.8853/91/$03.50 0 1991 - Elsevier Science Publishers B.V. All rights reserved