~ Solid State Communications, Vol. 89, No. 2, pp. 101-104, 1994. Printed in Great Britain. 0038-1098/9456.00+.00 Pergamon Press Ltd STUDY OF CRYSTALLIZATION PROCESS OF METGLASS Fe B 86 14 BY M~SSBAUER EFFECT AND RESISTIVITY MEASUREMENTS M. Arshed, M. Siddique, M. Anwar-ul-Islam, N.M. Butt Pakistan Institute of Nuclear Science & Technology P.O. Nilore, Islamabad, Pakistan A. Ashfaq and A. Shamim Centre for Solid State Physics, Punjab University, Lahore, Pakistan (Received 9 June 1993 by M. Cardona) Both isochronal resistivity measurements and phase identification using MSssbauer effect in amorphous alloy Fe86B]4, quenched at selected temperatures from 300 to 925K, show three main stages. The slight rise in resistivity in stage I, 300 to 550K, may be because of ~,-FeB which is the only phase which crystallizes in this stage. The decrease in resistivity in stage II, 550 to 735K, is due to the formation of ct-Fe, Fe B and Fe B. The appearance of a step 2 3 in resistivity curve in this stage, from 640 to 680K, can be attributed to ~'-FeB, whose percentage increases appriciably in the same interval of temperature. In stage Ill, 735 to 925K, where the crystallization seems to be complete, the sharp rise in resistivity may be because of lattice scattering of electrons. In this stage ct-Fe, ~'-FeB and Fe2B are present. ~-FeB is the first phase to crystallize from the amorphous phase instead of ct-Fe as previously reported. Introduction Study of crystallization process in amorphous alloys is important for their technological applications. Crystallization in such alloys proceeds through different stages of reaction, with the formation of stable and metastable phases. Crystallization process can be studied with various techniques. Some techniques can inform only about the phase transition temperatures, e.g. DSC (differential scanning calorimetery) and resistivity measurements, while some techniques, including MSssbauer effect, are capable of providing information about the composition of phases formed due to crystallization, their relative abundance and their structure related properties. MSssbauer spectroscopy is also considered to be the best for the study of crystallization process in amorphous alloys regarding the phase identification, type of ordering and sequence of precipitation of crystalline phases [1]. In resistivity measurements the amorphous sample is heated at a certain constant rate upto the equilibrium state (-~ 90OK). For Fe-B system, the 101 resistivity rises slightly upto a certain temperature followed by a dip in resistivity vs temperature curve [2,3]. However, the appearance of various steps in the curve differs from composition to composition ([2,3] and Fig.1 of this paper}. This difference can be attributed to the sequence of formation of various Fe-B phases. One way to correlate the resistivity with the kind of phases formed is the quenching of the samples at various temperatures during their crystallization process. In this Study MSssbauer effect in combination with resistivity measurements has been used to study crystallization process in metglass Fe B . First of all resistivity 86 14 measurements were made upto 925K and then critical temperatures on the resistivity-temperature curve were selected at which samples were quenched for MSssbauer measurements, to identify the phases. To the best of our knowledge no such measurements have been reported except by Nakajima et al [4] who made MSssbauer effect measurements on Fe B 86 14 in the vicinity of two exothermics of DSC.