Magnetic Modes in Rare Earth Perovskites: A Magnetic-Field-Dependent Inelastic Light Scattering study

Saha, Surajit; Cao, Bingchen; Motapothula, M.; Cong, Chunxiao; Sarkar, Tarapada; Srivastava, Amar; Sarkar, Soumya; Patra, Abhijeet; Ghosh, Siddhartha; Ariando, Ariando; Coey, J. M. D.; Yu, Ting; Venkatesan, T.

doi:10.1038/srep36859

Cited by 8 publications

(5 citation statements)

References 34 publications

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“…Those peaks do not appear in our complementary measurements performed with a different excitation wavelength (532 nm), and we therefore conclude that they are not Raman peaks but rather originate from some luminescence processes. Their detailed assignment is beyond the scope of this work, but we note that they are very similar in positions, shape, and temperature behaviour to the lines observed in the Raman spectra of LaAlO 3 , which have been assigned to various intrinsic defects [44].…”

Section: A Lattice Dynamics Calculationsmentioning

confidence: 58%

Lattice dynamics and Raman spectrum of BaZrO3 single crystals

et al. 2019

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BaZrO3 is a perovskite that remains in the simple cubic phase at all temperatures, hence with no first-order Raman-active phonon mode allowed by symmetry. Yet, it exhibits an intense Raman spectrum with sharp and well-defined features. Here, we report the evolution of the Raman spectrum of BaZrO3 single crystals in a broad temperature range (4-1200 K) and discuss its origin with the support of detailed first-principle calculations of the lattice dynamics. Phonon calculations are performed not only for the cubic phase of BaZrO3, but also for the low-symmetry phases with octahedra tilts that have been suspected to exist at the nanoscale. We show that the Raman spectrum shows no direct evidence for these nanodomains, but can instead be explained by classical second-order Raman scattering. We provide an assignment of the dominant features to phonon modes combinations. In particular, we show that the high frequency range of the spectrum is dominated by overtones and shows an image of the phonon density of states corresponding to the stretching modes of the oxygen octahedra.

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Section: A Lattice Dynamics Calculationsmentioning

confidence: 58%

Lattice dynamics and Raman spectrum of BaZrO3 single crystals

et al. 2019

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“…This is demonstrated by the observation that they are found at different positions in BZO1 grown in the present work and in the commercial BZO2 and BZO3 samples. Such spurious Raman lines are not uncommon in perovskites [62], but cannot be assigned conclusively here.…”

Section: Raman Spectroscopy Analysismentioning

confidence: 67%

Single crystal growth of BaZrO₃ from the melt at 2700 °C using optical floating zone technique and growth prospects from BaB₂O₄ flux at 1350 °C

et al. 2019

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We report the growth of BaZrO 3 single crystals by the optical floating zone technique and the investigation on its flux growth using BaB 2 O 4 as a solvent. 6-mm long colorless and transparent single crystals were obtained with a mirror furnace without the need for post-treatment annealing.Its properties are determined and compared with those of two commercial crystals grown by the tri-arc Czochralski method. The chemical composition was investigated using glow discharge mass spectrometry (GDMS) and secondary ion mass spectrometry (SIMS), which indicate minor impurities of Sr, Hf, Ca and Ti, with maximal concentrations for Sr and Hf in the range of 0.3-0.5 % at. The optical band gap determined by UV-visible spectroscopy is found to be ~4.8 eV and Page 1 of 25 CrystEngComm 2indicates the high quality of the BaZrO 3 crystals grown by the optical floating zone technique.Raman spectroscopy at ambient conditions and at low temperatures down to 4.2 K reveals a relatively sharp second-order spectrum and does not reveal any structural phase transition.

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“…Figure presents the Raman spectra of AmAlO 3 and PuAlO 3 . Group theory predicts five (A 1g + 4E g ) , Raman active modes for the R 3̅ c space group of rhombohedral AmAlO 3 . A first “soft” E g mode has been reported for similar trivalent lanthanide aluminates to occur at low energy (<40 cm –1 ) and is therefore not in the wavenumber range of this experimental investigation.…”

Section: Resultsmentioning

confidence: 99%

“…For comparison, the Raman spectra of NdAlO 3 and LaAlO 3 have also been (Table 5) with the same approach used for AmAlO 3 and PuAlO 3 , and the obtained spectra are in agreement with the literature data. 37,38 In Figure 6, the trends of the three main modes measured here are plotted as a function of the cationic radius for coordination number VI. The trend is rather regular for the three cases, confirming that the local coordination environment (bond distance, bond The infrared spectra of AmAlO 3 and PuAlO 3 are shown in Figure 7.…”

Section: Resultsmentioning

confidence: 99%

Plutonium and Americium Aluminate Perovskites

et al. 2019

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Both AmAlO3 and PuAlO3 perovskites have been synthesized and characterized using powder X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), and 27Al magic angle spinning nuclear magnetic resonance spectroscopy (MAS NMR). AmAlO3 perovskite showed a rhombohedral configuration (space group R3̅c) in agreement with previous studies. The effect of americium α-decay on this material has been followed by XRD and 27Al MAS NMR analyses. In a first step, a progressive increase in the level of disorder in the crystalline phase was detected, associated with a significant crystallographic swelling of the material. In a second step, the crystalline AmAlO3 perovskite was progressively converted into amorphous AmAlO3, with a total amorphization occurring after 8 months and 2 × 1018 α-decays/g. For the first time, PuAlO3 perovskite was synthesized with an orthorhombic configuration (space group Imma), showing an interesting parallel to CeAlO3 and PrAlO3 lanthanide analogues. High-temperature XRD was performed and showed a Imma → R3̅c phase transition occurring between 473 and 573 K. The thermal behavior of R3̅c PuAlO3 was followed from 573 to 1273 K, and extrapolation of the data suggests that cubic plutonium perovskite should become stable at around 1850 K (R3̅c → Pm3̅m transition).

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Magnetic Modes in Rare Earth Perovskites: A Magnetic-Field-Dependent Inelastic Light Scattering study

Cited by 8 publications

References 34 publications

Lattice dynamics and Raman spectrum of BaZrO3 single crystals

Lattice dynamics and Raman spectrum of BaZrO3 single crystals

Single crystal growth of BaZrO₃ from the melt at 2700 °C using optical floating zone technique and growth prospects from BaB₂O₄ flux at 1350 °C

Plutonium and Americium Aluminate Perovskites

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Magnetic Modes in Rare Earth Perovskites: A Magnetic-Field-Dependent Inelastic Light Scattering study

Cited by 8 publications

References 34 publications

Lattice dynamics and Raman spectrum of BaZrO3 single crystals

Lattice dynamics and Raman spectrum of BaZrO3 single crystals

Single crystal growth of BaZrO3 from the melt at 2700 °C using optical floating zone technique and growth prospects from BaB2O4 flux at 1350 °C

Plutonium and Americium Aluminate Perovskites

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Resources

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Single crystal growth of BaZrO₃ from the melt at 2700 °C using optical floating zone technique and growth prospects from BaB₂O₄ flux at 1350 °C