Premium
Thermal behavior in Pr(HCOO) 3 crystals
Author(s) -
Moura M. R.,
Ayala A. P.,
Mendes Filho J.,
Guedes I.,
Paschoal C. W. A.,
Leyva A. G.,
Polla G.,
Vega D.,
de Perazzo P. K.,
Lanza H.
Publication year - 2004
Publication title -
journal of raman spectroscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.748
H-Index - 110
eISSN - 1097-4555
pISSN - 0377-0486
DOI - 10.1002/jrs.1124
Subject(s) - raman spectroscopy , atmospheric temperature range , anomaly (physics) , chemistry , phonon , differential scanning calorimetry , phase (matter) , crystal (programming language) , thermal , differential thermal analysis , transformation (genetics) , crystal structure , thermal analysis , crystallography , analytical chemistry (journal) , thermodynamics , condensed matter physics , optics , physics , organic chemistry , diffraction , computer science , programming language , biochemistry , gene
This paper reports a thermal and spectroscopic study of Pr(HCOO) 3 crystal in the range 300–10 K. Room temperature Raman phonons are assigned based on group theory analysis and correlations with other rare earth formates. Differential scanning calorimetric (DSC) measurements show that there is a slight anomaly in the behavior of the heat capacity at around 140 K. Temperature‐dependent Raman spectra were recorded and the changes observed are discussed. These results suggest that Pr(HCOO) 3 undergoes a second‐order phase transformation at temperatures lower than 140 K. Based on the group‐to‐subgroup relations, we propose a possible low‐temperature structure and discuss the driving mechanism of the phase transformation. Copyright © 2004 John Wiley & Sons, Ltd.