One-step synthesis at room temperature of low dimensional perovskite single crystals with high optical quality

2020 ◽  
Vol 221 ◽  
pp. 117079 ◽  
Author(s):  
Marco Cinquino ◽  
Laura Polimeno ◽  
Giovanni Lerario ◽  
Milena De Giorgi ◽  
Anna Moliterni ◽  
...  
2007 ◽  
Author(s):  
S. M. Hegde ◽  
K. L. Schepler ◽  
R. D. Peterson ◽  
D. E. Zelmon

1997 ◽  
Vol 478 ◽  
Author(s):  
T. M. Tritt ◽  
M. L. Wilson ◽  
R. L. Littleton ◽  
C. Feger ◽  
J. Kolis ◽  
...  

AbstractWe have measured the resistivity and thermopower of single crystals as well as polycrystalline pressed powders of the low-dimensional pentatelluride materials: HfTe5 and ZrTe5. We have performed these measurements as a function of temperature between 5K and 320K. In the single crystals there is a peak in the resistivity for both materials at a peak temperature, Tp where Tp ≈ 80K for HfTe5 and Tp ≈ 145K for ZrTe5. Both materials exhibit a large p-type thermopower around room temperature which undergoes a change to n-type below the peak. This data is similar to behavior observed previously in these materials. We have also synthesized pressed powders of polycrystalline pentatelluride materials, HfTe5 and ZrTe5. We have measured the resistivity and thermopower of these polycrystalline materials as a function of temperature between 5K and 320K. For the polycrystalline material, the room temperature thermopower for each of these materials is relatively high, +95 μV/K and +65 μV/K for HfTe5 and ZrTe5 respectively. These values compare closely to thermopower values for single crystals of these materials. At 77 K, the thermopower is +55 μV/K for HfTe5 and +35 μV/K for ZrTe5. In fact, the thermopower for the polycrystals decreases monotonically with temperature to T ≈ 5K, thus exhibiting p-type behavior over the entire range of temperature. As expected, the resistivity for the polycrystals is higher than the single crystal material, with values of 430 mΩ-cm and 24 mΩ-cm for Hfre5 and ZrTe5 respectively, compared to single crystal values of 0.35 mΩ-cm (HfTe5) and 1.0 mΩ-cm (ZrTe5). We have found that the peak in the resistivity evident in both single crystal materials is absent in these polycrystalline materials. We will discuss these materials in relation to their potential as candidates for thermoelectric applications.


2010 ◽  
Vol 96 (4) ◽  
pp. 043101 ◽  
Author(s):  
Damien Bordel ◽  
Denis Guimard ◽  
Mohan Rajesh ◽  
Masao Nishioka ◽  
Emmanuel Augendre ◽  
...  

1994 ◽  
Author(s):  
Dmitry Y. Sugak ◽  
Andrej O. Matkovskii ◽  
E. A. Korobenko ◽  
Anatolij I. Mikhalevych ◽  
Ivan M. Solskii ◽  
...  

2013 ◽  
Vol 11 (7) ◽  
pp. 1163-1171
Author(s):  
Judita Šukytė ◽  
Remigijus Ivanauskas

AbstractThe preparative conditions were optimized to get chalcogens layers on the polymer — polyamide PA surface by sorption at room temperature using sodium telluropentathionate, Na2TeS4O6. Further interaction of chalcogenized dielectric with copper’s (I/II) salt solution leads to the formation of mixed CuxSy-CuxTey layers. Optical, electrical and surface characteristics of the layers are highly controlled by the deposition parameters. The stoichiometry of these layers was established by UV-Visible and AA spectrometry. Optical absorption (transmittance) experiments show the samples are of high optical quality. The band gaps of thin films were obtained from their optical absorption spectra, which were found in the range of 1.44–2.97 eV. XRD was used in combination with AFM to characterize chalcogenides layers’ structural features. XRD analysis confirmed the formation of mixed copper chalcogenides’ layers in the surface of PA with binary phases such as Cu2Te, Cu3.18Te2, copper telluride, Cu2.72Te2, vulcanite, CuTe, anilite, Cu7S4 and copper sulfide, Cu1.8S. The crystallite sizes of thin films calculated by the Scherer formula were found to be in the range of 3.07–13.53 nm for CuxSy crystallites and 4.06–20.79 nm for CuxTey crystallites. At room temperature an electrical resistance of CuxSy-CuxTey layers varies from 3.0×103 kΩ□−1 to 1.0 kΩ□−1.


Author(s):  
S. Haussühl ◽  
J. Schreuer

AbstractLarge single crystals of optical quality of (±)-tris(ethylenediamine)cobalt(III) nitrate have been grown from aequeous solutions. An X-ray structure analysis yielded space groupPyroelectric, dieletric, piezoelectric and elastic constants have been determined at room temperature. Additionally, we have studied the coefficients of thermal expansion and the thermoelastic constants in the range between 270 K and 350 K. The structure exhibits a nearly trigonal symmetry around the [unk]


1999 ◽  
Vol 607 ◽  
Author(s):  
B. H. Bairamov ◽  
N. Fernelius ◽  
G. Irmer ◽  
J. Monecke ◽  
I. K. Polushina ◽  
...  

AbstractInelastic light scattering by optical phonons and the temperature dependent electrical conductivity, Hall constant and photosensitivity were studied in oriented CdGeAs2 crystals grown by ultra-low gradient freeze technique from near-stoichiometric melts. Observation of the clear polarization dependence of the inelastic light scattering spectra by optical phonons combined with the absence of any dependence of the intensity and frequency shift of the observed lines with mapping measurements in 300 μm steps indicated the high optical quality and homogeneity of these single crystals. It is shown that surface-barrier structures using these single crystals may be used as wide-band detectors for natural light, as well as selective photoanalyzers for linearly polarized radiation.


CrystEngComm ◽  
2022 ◽  
Author(s):  
Inga Vasilyeva ◽  
Ruslan Nikolaev

Advances and limitations in the field of growing large, a high optical quality single crystals of AgGaS2 (AGS), AgGaGeS4 (AGGS), ZnGeP2 (ZGP), LiInS2 (LIS), LiGaS2 (LGS), LiInSe2 (LISe), LiGaSe2 (LGSe)...


Author(s):  
Софья Михайловна Маслобоева

Проведен анализ известных методов синтеза шихты ниобата лития, легированной бором, которая используется при выращивании монокристаллов высокого оптического качества методом Чохральского. Установлено, что способ гомогенного легирования (шихта получается из прекурсора NbO :B и LiCO) по сравнению с твердофазным (шихта получается из смеси LiCO: NbO : HBO ) позволяет выращивать кристаллы LiNbO: B с более однородным распределением в них примеси бора, а также в объеме расплава, при этом упрощаются технологические режимы, устанавливаемые при росте кристаллов. В работе впервые рассмотрен жидкофазный метод синтеза шихты, исключающий стадию прокалки гомогенизированной смеси пентаоксида ниобия и карбоната лития. Результаты имеют важное значение при выборе технологии выращивания легированных бором монокристаллов ниобата лития для конкретных областей техники. Known methods of a boron doped lithium niobate charge synthesis were analyzed. Such a charge is applied for the growth by Czochralski of single crystals with high optical quality. Homogeneous doping (the charge is obtained from precursor NbO:B and LiCO) was compared with solid phase doping (the charge is obtained from the mixture LiCO: NbO: HBO). Homogeneous doping was determined to help produce LiNbO: B crystals with a more uniform distribution of a boron dopant, boron distributes more uniform in the melt volume; technological regimes established during crystal growth become easier. For the first time the paper considers liquid-phase charge synthesis method; the method excludes the stage of annealing of homogenized mixture of niobium pentoxide and lithium carbonate. Results are crucial for the choice of technology at growing of boron doped lithium niobate crystals for exact areas of technics.


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