Berlin 2012 – scientific programme
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MM: Fachverband Metall- und Materialphysik
MM 59: Complex Materials II
MM 59.4: Talk
Thursday, March 29, 2012, 17:45–18:00, H 1029
Thermal stability and soft magnetic properties of Co-Fe-Hf-B glassy alloy with wide supercooled liquid region — •Amir Hossein Taghvaei1,2, Mihai Stoica1, Uta Kühn1, and Jürgen Eckert1 — 1IFW Dresden, Germany — 2Shiraz University, Shiraz, Iran
A new glassy alloy with composition of Co40Fe22Hf6.5B31.5 was synthesized by melt spinning method. The thermal stability and crystallization process were investigated by differential scanning calorimetry (DSC) and X-Ray diffraction (XRD) in reflection mode using Co Kα radiation. The DSC profile of ribbons showed the glass transition at 903 K, followed by a supercooled liquid region of 62 K before crystallization. The glassy phase devitrified through a single sharp exothermic peak in to (Co, Fe)2B, (Co, Fe)3HfB2 and (Co, Fe)21Hf2B6 intermetallic compounds. The activation crystallization energy of 912 KJ/mole measured using the Kissinger approach, confirmed the very high thermal stability of this alloy. Magnetic measurements indicated that the as cast ribbon has the coercivity, magnetization and Curie temperature of 5 A/m, 47 Am2/kg and 431 K, respectively.The high thermal stability can be explained by the sluggish nucleation and slow growth of the complex (Co, Fe)3HfB2 and (Co, Fe)21Hf2B6 intermetallics.