Solid transition metal oxyfluorides

Mel'nichenko, E. I.; Gorbenko, O. Yu.; Laptash, N. M.; Polyshchuk, S. A.

doi:10.1016/s0022-1139(00)84427-9

“…Recently, there has been a significant interest in investigation of a series of mixed-anion inorganic compounds. 1,2 Classic examples are condensed oxyhydrides [3][4][5][6][7][8][9][10] and oxyfluorides; [11][12][13][14] they are of peculiar interest to the development of new generation of perspective functional materials. As it was reported in a number of the experimental and theoretical studies of bulk phases of yttrium oxyhydrides, [15][16][17][18][19] the anionic nature of these compounds is such that in the condensation process one can flexibly control structural, elastic and charge degrees of freedom by manipulating anion configurations in terms of O/H ratio.…”

Section: Introductionmentioning

confidence: 99%

Exploring The Anion Chemical Space: A Model of Electroelastic Material Ln2OF2-xClxH2 (Ln=Y,La,Gd) with High Mechanical Sensitivity and Remarkable Energy Harvesting

Strugovshchikov¹,

Pishtshev²

2020

Preprint

0

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The main result of our investigation is the prediction of a new family of multi-anion compounds - Ln2OF2-xClxH2 (Ln=Y,La,Gd) which due to anomalous elastic behaviour could present interest for the design and development of electromechanical devices. The composition Ln2OF2-xClxH2 utilizes complex heteroatomic anion [OF2-xClxH2]-6; in a solid state, as it follows from the DFT calculations, the system crystallizes into a columnar-type layered structure of P3m1 or R3m trigonal symmetries in which the LnO(F,Cl)H and Ln(F,Cl)FH layers are uniformly stacked in an alternating order along the high-symmetry c axis. In the trigonal lattice without inversion center, the resulting two-layers geometry puts groups of the anionic species together in a way that gives rise to the strong localization of valence charge density. We showed that being globally stable, such specific crystal architecture may lead to a high asymmetry of mechanical and electrical responses with respect to imposed loads. Moreover, small dynamic changes of the equilibrium charge and bonding configurations may cause rather the enhanced structural sensitivity of elastic responses at low pressures. Comparison of electromechanical characteristics showed that the predicted materials can serve as direct successors of the line of PVDF piezopolymers.

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“…Recently, there has been a significant interest in investigation of a series of mixed-anion inorganic compounds. 1,2 Classic examples are condensed oxyhydrides [3][4][5][6][7][8][9][10] and oxyfluorides; [11][12][13][14] they are of peculiar interest to the development of new generation of perspective functional materials. As it was reported in a number of the experimental and theoretical studies of bulk phases of yttrium oxyhydrides, [15][16][17][18][19] the anionic nature of these compounds is such that in the condensation process one can flexibly control structural, elastic and charge degrees of freedom by manipulating anion configurations in terms of O/H ratio.…”

Section: Introductionmentioning

confidence: 99%

Exploring The Anion Chemical Space: A Model of Electroelastic Material Ln2OF2-xClxH2 (Ln=Y,La,Gd) with High Mechanical Sensitivity and Remarkable Energy Harvesting

Strugovshchikov

¹

,

Pishtshev²

2020

Preprint

0

View full text Add to dashboard Cite

The main result of our investigation is the prediction of a new family of multi-anion compounds - Ln2OF2-xClxH2 (Ln=Y,La,Gd) which due to anomalous elastic behaviour could present interest for the design and development of electromechanical devices. The composition Ln2OF2-xClxH2 utilizes complex heteroatomic anion [OF2-xClxH2]-6; in a solid state, as it follows from the DFT calculations, the system crystallizes into a columnar-type layered structure of P3m1 or R3m trigonal symmetries in which the LnO(F,Cl)H and Ln(F,Cl)FH layers are uniformly stacked in an alternating order along the high-symmetry c axis. In the trigonal lattice without inversion center, the resulting two-layers geometry puts groups of the anionic species together in a way that gives rise to the strong localization of valence charge density. We showed that being globally stable, such specific crystal architecture may lead to a high asymmetry of mechanical and electrical responses with respect to imposed loads. Moreover, small dynamic changes of the equilibrium charge and bonding configurations may cause rather the enhanced structural sensitivity of elastic responses at low pressures. Comparison of electromechanical characteristics showed that the predicted materials can serve as direct successors of the line of PVDF piezopolymers.

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