Activation Energies of Crystallization in Amorphous RMn_{4.5}Ge_{4.5}Fe_{1.5}Al_{1.5} (R = La, Y, Dy) Alloys

• Authors: Z. Śniadecki , U. Rößler , B. Idzikowski
• Languages of publication: EN

Abstracts

EN

The effective activation energies, characteristic crystallization temperatures and enthalpies of amorphous RMn_{4.5}Ge_{4.5}Fe_{1.5}Al_{1.5} (R = Y, La, Dy) alloys produced using melt-spinning technique were investigated by differential scanning calorimetry. X-ray diffraction measurements were performed for as-quenched and annealed samples. The crystalline structure of annealed YMn_{4.5}Ge_{4.5}Fe_{1.5}Al_{1.5} and DyMn_{4.5}Ge_{4.5}Fe_{1.5}Al_{1.5} alloys was determined as orthorhombic TbFe_6Sn_6-type with Cmcm (63) space group. The alloy with Y appears as a more useful non-magnetic analogue for DyMn_{4.5}Ge_{4.5}Fe_{1.5}Al_{1.5} than the La-based alloy. The differential scanning calorimetry curves for Dy- and Y-based alloys also exhibit similar thermal behavior. The effective activation energies E_a were determined using the Kissinger approach and high values up to 778±74 kJ/mol for La-based sample were established. The comparison of Y-, La-, and Dy-based alloys suggests improvement of thermal stability with the increase in rare-earth element atomic radius in the glassy RMn_{4.5}Ge_{4.5}Fe_{1.5}Al_{1.5} systems.

Keywords

EN

61.43.Dq   61.82.Bg   75.50.Kj   81.70.Pg  

• Publisher: Institute of Physics, Polish Academy of Sciences
• Journal: Acta Physica Polonica A
• Year: 2009
• Volume: 115
• Issue: 1
• Pages: 409-412

Dates

published

2009-01

References

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Identifiers

DOI

10.12693/APhysPolA.115.409