%0 Journal Article %1 WOS:000400718500013 %A Saraiva, G D %A Paraguassu, W %A Freire, P T C %A de Castro, A J Ramiro %A de Sousa, F F %A Filho, J Mendes %C PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS %D 2017 %I ELSEVIER SCIENCE BV %J JOURNAL OF MOLECULAR STRUCTURE %K High Phase Raman Trigonal molybdate; phase} scattering; temperature; transformations; {Dilithium %P 119-124 %R 10.1016/j.molstruc.2017.03.038 %T Temperature induced phase transformations on the Li2MoO4 system studied by Raman spectroscopy %V 1139 %X The present research reports results of lattice dynamics calculations and temperature-dependent Raman scattering study of the dilithium molybdate system, Li2MoO4, in the 25-600 C-circle temperature range. The effects of the temperature duly produced gradual changes, associated with the disorder and anharmonic effects followed by thermodynamic instability, leading the structure to a phase transformation. Calorimetric measurements up to 1000 C-circle corroborated that the crystal structure experienced gradual modifications, characterized by changes in the DSC base line. These stated thermal events as well as the changes in the profile of the Raman spectra, suggested that a phase transformation is connected with tilting and/or rotations of the MoO4 tetrahedron leading to a disorder in the MoO4 sites. The observation of one exothermic peak on the DSC curve at about 702 C-circle is related with the melting in the sample. The experimental results were discussed based on the mode assignments performed by using lattice dynamics calculations from where we predicted both wavenumbers and atomic displacements. (C) 2017 Elsevier B.V. All rights reserved.

@article{WOS:000400718500013, abstract = {The present research reports results of lattice dynamics calculations and temperature-dependent Raman scattering study of the dilithium molybdate system, Li2MoO4, in the 25-600 C-circle temperature range. The effects of the temperature duly produced gradual changes, associated with the disorder and anharmonic effects followed by thermodynamic instability, leading the structure to a phase transformation. Calorimetric measurements up to 1000 C-circle corroborated that the crystal structure experienced gradual modifications, characterized by changes in the DSC base line. These stated thermal events as well as the changes in the profile of the Raman spectra, suggested that a phase transformation is connected with tilting and/or rotations of the MoO4 tetrahedron leading to a disorder in the MoO4 sites. The observation of one exothermic peak on the DSC curve at about 702 C-circle is related with the melting in the sample. The experimental results were discussed based on the mode assignments performed by using lattice dynamics calculations from where we predicted both wavenumbers and atomic displacements. (C) 2017 Elsevier B.V. All rights reserved.}, added-at = {2022-05-23T20:00:14.000+0200}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, author = {Saraiva, G D and Paraguassu, W and Freire, P T C and de Castro, A J Ramiro and de Sousa, F F and Filho, J Mendes}, biburl = {https://www.bibsonomy.org/bibtex/2162b98635f4a1236f98e2105fb2d1807/ppgfis_ufc_br}, doi = {10.1016/j.molstruc.2017.03.038}, interhash = {b93edd39d289709fe72b795a52432bcd}, intrahash = {162b98635f4a1236f98e2105fb2d1807}, issn = {0022-2860}, journal = {JOURNAL OF MOLECULAR STRUCTURE}, keywords = {High Phase Raman Trigonal molybdate; phase} scattering; temperature; transformations; {Dilithium}, pages = {119-124}, publisher = {ELSEVIER SCIENCE BV}, pubstate = {published}, timestamp = {2022-05-23T20:00:14.000+0200}, title = {Temperature induced phase transformations on the Li2MoO4 system studied by Raman spectroscopy}, tppubtype = {article}, volume = 1139, year = 2017 }