Octahedral rotations in Ruddlesden-Popper layered oxides under pressure from first principles

Pressure-Induced Phase Transformations of Quasi-2D Sr3Hf2O7

“…Almost all materials will undergo several phase-transitions under compression, thus generating new polymorphs with promising properties, different to those properties of materials under room conditions. It has been found that factors which are known to control the ABO 3 perovskites pressure response, such as the A- and B-site cation formal charges, the tolerance factor, and the B-site chemical environments, also affect the pressure response of the layered perovskites . Therefore, the interest in applying pressure to probe the structural, electronic, and vibrational properties to such structures.…”

“…Moreover, it has been evidenced that the O octahedra tilt and rotation modes of Ca 3 Ti 2 O 7 undergo softening when hydrostatic pressure or heating is considered. , This behavior under temperature and pressure reveals the softness of the antiphase tilt, which indicates the importance of the partially occupied d -orbitals of the transition metal ions, since these determine the stability of the oxygen octahedra distortion. , Moreover, through Raman measurements, it was observed that under isotropic pressure, the polyhedra tilts of the Ca 3 Mn 2 O 7 compound can be suppressed within the low-pressure regime (1.4–2.3 GPa) . On the other hand, through DFT calculations (0 K) performed on the Ca 3 Ti 2 O 7 compound, it was recently found by computing the enthalpies for several pressure values, up to 20 GPa, that in fact the Ccce phase can become energetically more favorable than Cmc 2 1 , with the transition occurring slightly below 15 GPa …”

“…25 On the other hand, through DFT calculations (0 K) performed on the Ca 3 Ti 2 O 7 compound, it was recently found by computing the enthalpies for several pressure values, up to 20 GPa, that in fact the Ccce phase can become energetically more favorable than Cmc2 1 , with the transition occurring slightly below 15 GPa. 20 The goal of this work is to inspect, through first-principles calculations, the evolution of the structural properties and the energetic and dynamic stabilities of the Cmc2 1 and Ccce structural phases of the SHO compound for increasing values of applied hydrostatic pressure. Furthermore, enthalpy results on the I4/mmm and C2/c structural phases have also been computed.…”

“…It has been found that factors which are known to control the ABO 3 perovskites pressure response, such as the A- and B-site cation formal charges, the tolerance factor, and the B-site chemical environments, also affect the pressure response of the layered perovskites. 20 Therefore, the interest in applying pressure to probe the structural, electronic, and vibrational properties to such structures.…”

Theoretical occurrence of quantized chemistry of conduction mechanism in layered perovskite for the application of Resistive Random Access Memory devices

“…Ternary perovskite has the specified form of ABO 3 with the far-reaching extent of exercising within the contrastive field of optoelectronics, owing to its exuberant potentiality to alter the electromagnetic waves in the visible range into electrical energy [13,14], and, consequently, the class of Ruddlesden-Popper's (RP) with the general formula A n+1 B n O 3n+1 of layered ternary perovskite plays a vital role in the diverse domain of RRAM due to its insignificant and phenomenal properties [1]. Remarkable properties such as superconductivity, piezoelectricity, metal-insulator transition [15], and low power consumption [16] make the layered perovskite materials methodologically foremost. Tian et al [16] used the low power and energy aspects of RP perovskite for scaled-down RRAM.…”