scholarly journals Lattice Dynamics and Optoelectronic Properties of Vacancy-Ordered Double Perovskite Cs2TeX6 (X = Cl–, Br–, I–) Single Crystals

2021 ◽  
Author(s):  
Maria C. Folgueras ◽  
Jianbo Jin ◽  
Mengyu Gao ◽  
Li Na Quan ◽  
Julian A. Steele ◽  
...  
Keyword(s):  
Single Crystals ◽  
Lattice Dynamics ◽  
Double Perovskite ◽  
Optoelectronic Properties

scholarly journals Tuning the Structural and Optoelectronic Properties of Cs 2 AgBiBr 6 Double‐Perovskite Single Crystals through Alkali‐Metal Substitution

2020 ◽  
Vol 32 (40) ◽  
pp. 2001878
Author(s):  
Masoumeh Keshavarz ◽  
Elke Debroye ◽  
Martin Ottesen ◽  
Cristina Martin ◽  
Heng Zhang ◽  
...  
Keyword(s):  
Alkali Metal ◽  
Single Crystals ◽  
Double Perovskite ◽  
Optoelectronic Properties ◽  
Metal Substitution ◽  
Structural And Optoelectronic Properties

scholarly journals Optical Study of the Electronic Structure and Lattice Dynamics of NdBaMn2O6 Single Crystals

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Rea Divina Mero ◽  
Kirari Ogawa ◽  
Shigeki Yamada ◽  
Hsiang-Lin Liu
Keyword(s):  
Electronic Structure ◽  
Single Crystals ◽  
Lattice Dynamics ◽  
Degrees Of Freedom ◽  
Phonon Mode ◽  
Double Perovskite ◽  
Orbital Ordering ◽  
Raman Scattering Spectroscopy ◽  
Optical Absorption Band ◽  
A Charge

AbstractWe investigated the electronic structure and lattice dynamics of double perovskite NdBaMn2O6 single crystals through spectroscopic ellipsometry and Raman scattering spectroscopy. The optical absorption band centered at approximately 0.88 eV was assigned to on-site d–d transitions in Mn, whereas the optical feature at approximately 4.10 eV was assigned to charge-transfer transitions between the 2p state of O and 3d state of Mn. Analysis of the temperature dependence of the d-d transition indicated anomalies at 290 and 235 K. The activated phonon mode, which appeared at approximately 440 cm−1 alongside with the enhancement of the 270 cm−1 phonon mode, coupled strongly to the metal–insulator transition at 290 K, which was associated with a charge/orbital ordering. Moreover, the MnO6 octahedral breathing mode at 610 cm−1 exhibited softening at a temperature lower than 235 K (temperature of the antiferromagnetic phase transition), which revealed the strong coupling between the lattice and magnetic degrees of freedom. The spin–phonon coupling constant obtained was λ = 2.5 cm−1. These findings highlight the importance of charge–orbital–spin interactions in establishing NdBaMn2O6 phases with novel properties.

scholarly journals Tunable magnetization steps in mixed valent ferromagnet Eu2CoMnO6

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nara Lee ◽  
Jong Hyuk Kim ◽  
Dong Gun Oh ◽  
Hyun Jun Shin ◽  
Hwan Young Choi ◽  
...  
Keyword(s):  
Material Processing ◽  
Magnetic Properties ◽  
Single Crystals ◽  
Magnetic State ◽  
Hysteresis Loops ◽  
Double Perovskite ◽  
Processing Parameters ◽  
Perovskite Oxides ◽  
Efficient Approach ◽  
Isothermal Magnetization

AbstractMagnetic properties can be manipulated to enhance certain functionalities by tuning different material processing parameters. Here, we present the controllable magnetization steps of hysteresis loops in double-perovskite single crystals of Eu2CoMnO6. Ferromagnetic order emerges below TC ≈ 122 K along the crystallographic c axis. The difficulty in altering Co2+ and Mn4+ ions naturally induces additional antiferromagnetic clusters in this system. Annealing the crystals in different gas environments modifies the mixed magnetic state, and results in the retardation (after O2-annealing) and bifurcation (after Ar-annealing) of the magnetization steps of isothermal magnetization. This remarkable variation offers an efficient approach for improving the magnetic properties of double-perovskite oxides.

scholarly journals Gamma‐Ray Detection Using Bi‐Poor Cs 2 AgBiBr 6 Double Perovskite Single Crystals (Advanced Optical Materials 8/2021)

2021 ◽  
Vol 9 (8) ◽  
pp. 2170030
Author(s):  
Zheng Zhang ◽  
Da Cao ◽  
Zhengjie Huang ◽  
Evgeny O. Danilov ◽  
Ching‐Chang Chung ◽  
...  
Keyword(s):  
Single Crystals ◽  
Optical Materials ◽  
Gamma Ray ◽  
Double Perovskite

scholarly journals Growth and Characterisation of Layered (BA)2CsAgBiBr7 Double Perovskite Single Crystals for Application in Radiation Sensing

Crystals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1208
Author(s):  
Valeria Murgulov ◽  
Catherine Schweinle ◽  
Michael Daub ◽  
Harald Hillebrecht ◽  
Michael Fiederle ◽  
...  
Keyword(s):  
Single Crystals ◽  
Double Perovskite ◽  
Monoclinic Space Group ◽  
Trap States ◽  
Structure Property ◽  
X Ray ◽  
Structure Property Relationship ◽  
Lattice Planes ◽  
Radiation Sensors ◽  
Lower Resistivity

A recent publication on single crystals of two-dimensional, layered organic–inorganic (BA)2CsAgBiBr7 double perovskite (BA+ = ) suggested the great potential of this semiconductor material in the detection of X-ray radiation. Our powder XRD measurement confirms the crystallinity and purity of all samples that crystallise in the monoclinic space group , while the single crystal XRD measurements reveal the dominant {001} lattice planes. The structure–property relationship is reflected in the lower resistivity values determined from the van der Pauw measurements (1.65–9.16 × 1010 Ωcm) compared to those determined from the IV measurements (4.19 × 1011–2.67 × 1012 Ωcm). The density of trap states and charge-carrier mobilities, which are determined from the IV measurements, are 1.12–1.76 × 1011 cm–3 and 10−5–10−4 cm2V–1s–1, respectively. The X-ray photoresponse measurements indicate that the (BA)2CsAgBiBr7 samples synthesised in this study satisfy the requirements for radiation sensors. Further advances in crystal growth are required to reduce the density of defects and improve the performance of single crystals.

scholarly journals Crystal structures of the triple perovskites Ba2K2Te2O9and Ba2KNaTe2O9, and redetermination of the double perovskite Ba2CaTeO6

2018 ◽  
Vol 74 (7) ◽  
pp. 1006-1009 ◽  
Author(s):  
Matthias Weil
Keyword(s):  
Solid State ◽  
Single Crystals ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Perovskite Structure ◽  
Double Perovskite ◽  
Powder Diffraction Data ◽  
Space Group ◽  
X Ray ◽  
Group Type

Single crystals of Ba2K2Te2O9(dibarium dipotassium nonaoxidoditellurate), (I), Ba2KNaTe2O9(dibarium potassium sodium nonaoxidoditellurate), (II), and Ba2CaTeO6(dibarium calcium hexaoxidotellurate), (III), were obtained from KNO3/KI or KNO3/NaNO3flux syntheses in platinum crucibles for (I) and (II), or porcelain crucibles for (III). (I) and (II) are isotypic and are members of triple perovskites with general formulaA2[12co]A′[12co]B2[6o]B′[6o]O9. They crystallize in the 6H-BaTiO3structure family in space-group typeP63/mmc, with theA,A′,BandB′ sites being occupied by K, Ba, Te and a second Ba in (I), and in (II) by mixed-occupied (Ba/K), Ba, Te and Na sites, respectively. (III) adopts theA2[12co]B′[6o]B′′[6o]O6double perovskite structure in space-group typeFm-3m, with Ba, Ca and Te located on theA,B′ andB′′sites, respectively. The current refinement of (III) is based on single-crystal X-ray data. It confirms the previous refinement from X-ray powder diffraction data [Fuet al.(2008).J. Solid State Chem.181, 2523–2529], but with higher precision.

Growth of big single crystals of a new magnetic superconducting double perovskite Ba2PrRu1–xCuxO6

2006 ◽  
Vol 41 (2) ◽  
pp. 123-129 ◽  
Author(s):  
S. M. Rao ◽  
M. K. Wu ◽  
J. K. Srivastava ◽  
B. H. Mok ◽  
T. W. Chou ◽  
...  
Keyword(s):  
Single Crystals ◽  
Double Perovskite

scholarly journals Dimer rattling mode induced low thermal conductivity in an excellent acoustic conductor

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Ji Qi ◽  
Baojuan Dong ◽  
Zhe Zhang ◽  
Zhao Zhang ◽  
Yanna Chen ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Single Crystals ◽  
Layered Structure ◽  
First Principles ◽  
Sound Speed ◽  
Lattice Dynamics ◽  
Room Temperature ◽  
Lattice Thermal Conductivity ◽  
Atomic Structures ◽  
Order Of Magnitude

Abstract A solid with larger sound speeds usually exhibits higher lattice thermal conductivity. Here, we report an exception that CuP2 has a quite large mean sound speed of 4155 m s−1, comparable to GaAs, but single crystals show very low lattice thermal conductivity of about 4 W m−1 K−1 at room temperature, one order of magnitude smaller than GaAs. To understand such a puzzling thermal transport behavior, we have thoroughly investigated the atomic structures and lattice dynamics by combining neutron scattering techniques with first-principles simulations. This compound crystallizes in a layered structure where Cu atoms forming dimers are sandwiched in between P atomic networks. In this work, we reveal that Cu atomic dimers vibrate as a rattling mode with frequency around 11 meV, which is manifested to be remarkably anharmonic and strongly scatters acoustic phonons to achieve the low lattice thermal conductivity.

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