Author/Authors :
Mihalik، نويسنده , , M. and Posp??il، نويسنده , , J. and Rudajevov?، نويسنده , , A. and Marti، نويسنده , , X. and Wallacher، نويسنده , , D. and Hoser، نويسنده , , A. and Hofmann، نويسنده , , T. and Divi?، نويسنده , , M. and Sechovsk?، نويسنده , , V.، نويسنده ,
Abstract :
REIr2Si2 (RE = La, Ce, Pr and Nd) were found to be polymorphic compounds which can crystallize in two different tetragonal types of crystallographic structures (β-phase: CaBe2Ge2-type; α-phase: ThCr2Si2-type). Here we study the structural phase transitions (α- to β- and β- to α-) using thermal expansion, differential thermal analysis and neutron diffraction. Both phase transitions occur at temperatures lower than 1300 °C, have a hysteresis up to 300 °C, do not show any intermediate steps and are accompanied with the absorption/release of the latent heat. We conclude that these structural phase transitions are of the first order.
Keywords :
A. Rare-earth intermetallics , B. Phase transformation , C. Heat treatment , F. Diffraction
