Jornal de Química Física e Biofísica
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Abstrato

First-Principles Study of Pyroxene Structure LiVO3

Mohamed Khedidji*

In order to study the possible occurrence of the ferroelectric-paraelectric phase transition in the monoclinic LiVO₃, which remains experimentally ambiguous, we performed first-principles computations of the structural, dielectric and dynamical properties of LiVO₃ in its high-temperature paraelectric structure of C2/c symmetry. The results show that LiVO₃ exhibits three unstable phonon modes, which, after their condensation, lead to more stable phases of low symmetry. The obtained ground state phase is not ferroelectric, it is a non-polar phase of P2_1/c symmetry. However, the condensation of a low frequency mode obtained at 14 cm^-1 leads to the ferroelectric phase of Cc symmetry, which confirms that the ferroelectric- paraelectric phase transition is possible for monoclinic LiVO₃, which can then be controlled by applying an external parameter.