Structural phase transition of ternary dielectric SmGdO3: Evidence from angle dispersive x-ray diffraction and Raman spectroscopic studies

Abstract

High-pressure synchrotron based angle dispersive x-ray diffraction (ADXRD) studies were carried out on SmGdO 3 (SGO) up to 25.7 GPa at room temperature. ADXRD results indicated a reversible pressure-induced phase transition from ambient monoclinic to hexagonal phase at $8.9 GPa. The observed pressure-volume data were fitted with the third order Birch-Murnaghan equation of state yielding zero pressure bulk modulus B 0 ¼ 132 (22) and 177(9) GPa for monoclinic (B-type) and hexagonal (A-type) phases, respectively. Pressure dependent micro-Raman spectroscopy further confirmed the monoclinic to hexagonal phase transition at about 5.24 GPa. The mode Gr€ uneisen parameters and pressure coefficients for different Raman modes corresponding to each individual phases of SGO were calculated using pressure dependent Raman mode analysis. V C 2015 AIP Publishing LLC. [http://dx.

Structural and vibrational properties of phase-pure monoclinic NdLuO3 interlanthanides synthesized from nanostructured precursors

“…In addition, as already mentioned, 21 Raman-active modes were expected, with the following distribution in terms of the irreducible representations (i.r.) of the C 3 2h point group: 14A g 4 7B g [2,22,44]. In order to corroborate our findings and assign these non-polar gerade modes to their respective i.r., additional experiments were carried out by using polarized micro-Raman spectroscopy.…”

“…The standard solid-state reaction remains the major processing route for these materials [2,4], although other non-conventional methods are currently applied, such as reverse-strike coprecipitation [17], mechanochemical [18], thermal decomposition [5,6,13,19e21], sol-gel processing [22e24], combustion synthesis [25], molecular beam epitaxy technique [26,27], and hydroxide fluxes [12]. The hydrothermal technology is currently applied by our research group to synthesize nanostructured materials with technological interest [28e34].…”

Modification of the spectroscopic properties of Tb2O3 phosphor under the high-pressure phase transitions sequence

“…7), indicating an irreversible phase transition. Moreover, it is very similar to the monoclinic one reported for SmGdO 3 [36] or Gd 2 O 3 , [10] allowing us to infer that a structural phase transition A  B takes place. [34] and whose frequencies are also compared in Table 4.…”

Competing Interactions: Evolution of Inter and Intramolecular Hydrogen Bonds in Salicylic Acid at High Pressures

“…X-ray Diffraction. The in situ angle dispersive X-ray diffraction (ADXRD) measurements of powdered samples of salicylic acid at high pressures were carried out at beamline BL11 16 at the INDUS-2 synchrotron source (λ = 0.7841 Å) at RRCAT, Indore, India, employing a modified Mao−Bell diamond anvil cell. Copper was used as a pressure marker.…”