Browse
Submit Data
Databases
API
Help

Dataset Information

16 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Exploration of the Crystal Structure and Thermal and Spectroscopic Properties of Monoclinic Praseodymium Sulfate Pr₂(SO₄)₃.

ABSTRACT: Praseodymium sulfate was obtained by the precipitation method and the crystal structure was determined by Rietveld analysis. Pr₂(SO₄)₃ is crystallized in the monoclinic structure, space group C2/c, with cell parameters a = 21.6052 (4), b = 6.7237 (1) and c = 6.9777 (1) Å, β = 107.9148 (7)°, Z = 4, V = 964.48 (3) Å³ (T = 150 °C). The thermal expansion of Pr₂(SO₄)₃ is strongly anisotropic. As was obtained by XRD measurements, all cell parameters are increased on heating. However, due to a strong increase of the monoclinic angle β, there is a direction of negative thermal expansion. In the argon atmosphere, Pr₂(SO₄)₃ is stable in the temperature range of T = 30-870 °C. The kinetics of the thermal decomposition process of praseodymium sulfate octahydrate Pr₂(SO₄)₃·8H₂O was studied as well. The vibrational properties of Pr₂(SO₄)₃ were examined by Raman and Fourier-transform infrared absorption spectroscopy methods. The band gap structure of Pr₂(SO₄)₃ was evaluated by ab initio calculations, and it was found that the valence band top is dominated by the p electrons of oxygen ions, while the conduction band bottom is formed by the d electrons of Pr³⁺ ions. The exact position of ZPL is determined via PL and PLE spectra at 77 K to be at 481 nm, and that enabled a correct assignment of luminescent bands. The maximum luminescent band in Pr₂(SO₄)₃ belongs to the ³P₀ → ³F₂ transition at 640 nm.

SUBMITTER: Denisenko YG

PROVIDER: S-EPMC9267875 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Praseodymium(III) sulfate hydroxide, Pr(SO(4))(OH).

Project description:The title compound, Pr(SO(4))(OH), obtained under hydro-thermal conditions, consists of Pr(III) ions coordinated by nine O atoms from six sulfate groups and three hydroxide anions. The bridging mode of the O atoms results in the formation of a three-dimensional framework, stabilized by two O-H⋯O hydrogen-bonding inter-actions.

| S-EPMC3051512 | biostudies-literature

Synthesis, spectroscopic, thermal, crystal structure properties, and characterization of new Hofmann-Td-type complexes with 3-aminopyridine.

Project description:In this study, synthesis of two new tetracyanocadmate(II) and tetracyanozincate(II) complexes based on 3-aminopyridine (3AP) and investigation of their structural properties were reported. These complexes were characterized by using vibration spectroscopy, elemental, thermal analysis and single crystal X-ray diffraction (SC-XRD) techniques. Investigation of the elemental, spectral and single crystal data of these complexes showed that the formulas [Cd(3AP)2Zn(μ4-CN)4]n (1) and [Cd(3AP)2Cd(μ4-CN)4]n (2) fully explained their crystal structure. General information about the structural and chemical properties of these complexes obtained in single crystal form was obtained by observing the changes in the characteristic peaks of the 3AP with the [Zn(μ4-CN)4]2- and [Cd(μ4-CN)4]2- structures that make up these complexes. The behaviors of these complexes against changes in temperature were obtained by examining the temperature-dependent changes of their mass. The asymmetric unit of the heterometallic complexes 1 and 2 consist of half Cd(II) ion, half M ion [M = Zn1 in 1 and Cd2 in 2], two cyanide ligands and one 3AP.

| S-EPMC8326482 | biostudies-literature

Growth, structure, thermal properties and spectroscopic characteristics of Nd3+-doped KGdP4O12 crystal.

Project description:A single crystal of Nd3+-doped KGdP4O12 was successfully grown with the top-seeded solution growth and slow cooling (TSSG-SC) technique. It crystallizes in space group C2/c with cell parameters a = 7.812(2) Å, b = 12.307(3) Å, c = 10.474(2) Å, β = 110.84(3)° and Z = 4. The IR and Raman spectra also indicated that the phosphoric polyhedra of Nd:KGdP4O12 has a cyclic symmetry. The chemical composition of the crystal was analyzed and the distribution coefficient of Nd3+ was calculated. The crystal morphology of KGdP4O12 was identified using X-ray diffraction. The compound has good thermal stability to 920°C. Its specific heat and thermal conductivity were determined for potential applications. The spectral properties of Nd:KGdP4O12 indicates that it exhibits broad absorption and emission bands, which are attributed to low symmetry of the crystal. The broad absorption band around 798 nm has a full-width at half-maximum (FWHM) of 14.8 nm and is suitable for AlGaAs laser diode pumping. Moreover, 5 at% Nd3+-doped KGdP4O12 crystal has a long luminescence lifetime of 300 μs and a high quantum efficiency of 96%.

| S-EPMC4072700 | biostudies-literature

Crystal growth and negative thermal expansion properties of a Y2Mo4O15 single crystal.

Project description:A bulk-size single crystal of Y2Mo4O15 with 20 × 11 × 8 mm3 was successfully grown by the top-seed solution growth (TSSG) method. The full-width at half maximum of (100) and (010) crystal faces is 37 and 27 arcsec, respectively. The thermal conductivity coefficients κ 11, κ 22, κ 33, and κ 13 are determined to be 1.519, 2.097, 0.445, and 0.997 W m-1 K-1, respectively. It is worth noting that the Y2Mo4O15 crystal shows significant anisotropy thermal expansion properties, which exhibits a negative thermal expansion along the b-axis (α 22 = -5.11 × 10-6 K-1). The crystal structure analysis shows that the shrinking of Mo-O bond lengths along the b-axis with the increasing temperature would be the main origin of the negative thermal expansion properties for Y2Mo4O15 crystal, which does not comply with the current mechanism.

| S-EPMC10132451 | biostudies-literature

The Third Spectrum of Praseodymium (Pr iii) in the Vacuum Ultraviolet.

Project description:Measurements of the spectrum of doubly ionized praseodymium from 821 to 2103 Å are given. One hundred fifty-three energy levels deduced from these wavelengths and an earlier line-list of longer wavelengths are presented. These levels are identified with the configurations 4f26s, 4f27s, 4f28s, 4f26p, 4f26d, 4f25f, 5d24f, and 4f5d6s and are given term designations. Radial energy integrals belonging to these configurations are parametrically deduced from the known levels. A value of 21.625 eV (174420 cm-1) for the ionization energy of Pr iii, with an estimated uncertainty of 0.016 eV (130 cm-1), is derived from the 4f2ns series (n = 6, 7, 8).

| S-EPMC6728461 | biostudies-literature

Propagation of terahertz waves in a monoclinic crystal BaGa4Se7.

Project description:The complex symmetric dielectric tensor of a monoclinic crystal cannot be diagonalized by a space rotation operation in general, which poses a serious difficulty in analyzing the propagation of electromagnetic fields in monoclinic crystals so far. This propagation issue is discussed in a general case without using the index ellipsoid scheme. It is found that, when incident waves travel along the mirror plane normal or 2-fold rotation axis of monoclinic crystals, two eigenmodes following specific dispersion relations are elliptically polarized with the same ellipticity and chirality but have spatially orthogonal elliptical principal axes. The frequency independent features are the unique manifestation of the crystal symmetry. Using polarization sensitive terahertz time-domain spectroscopy and our developed data analyzing and processing methods, three complex permittivity tensor elements for a monoclinic crystal BaGa4Se7 are straightforwardly extracted and the properties of the two eigenmodes are characterized in full. It is also interesting that the spectral components beyond 1.7 THz show a very high refraction index (>10) and low dissipation during propagation, which suggests that the bulk phonon-polariton waves may be excited and effectively propagate in the crystal, resulting from the coherent phonon excitations by the incident terahertz waves. Our results may promote to develop novel terahertz devices based on polariton excitation and propagation in monoclinic crystals.

| S-EPMC6212440 | biostudies-literature

Evaluation of spectroscopic properties of Er(3+)/Yb(3+)/Pr(3+): SrGdGa3O7 crystal for use in mid-infrared lasers.

Project description:Er(3+)/Yb(3+)/Pr(3+): SrGdGa3O7 crystal was firstly grown by Czochralski method. Detailed spectroscopic analyses of Er(3+)/Yb(3+)/Pr(3+): SrGdGa3O7 were carried out. Besides better absorption characteristic, the spectra of Er(3+)/Yb(3+)/Pr(3+): SrGdGa3O7 show weaker up-conversion and near-infrared emissions as well as superior mid-infrared emission in comparison to Er(3+): SrGdGa3O7 and Er(3+)/Yb(3+): SrGdGa3O7 crystals. Furthermore, the self-termination effect for Er(3+) 2.7 μm laser is suppressed successfully because the fluorescence lifetime of the (4)I(13/2) lower level of Er(3+) decreases markedly while that of the upper (4)I(11/2) level changes slightly in Er(3+)/Yb(3+)/Pr(3+): SrGdGa3O7 crystal. The sensitization effect of Yb(3+) and deactivation effect of Pr(3+) ions as well as the energy transfer mechanism in Er(3+)/Yb(3+)/Pr(3+): SrGdGa3O7 crystal were also studied in this work. The introduction of Yb(3+) and Pr(3+) is favorable for achieving an enhanced 2.7 μm emission in Er(3+)/Yb(3+)/Pr(3+): SrGdGa3O7 crystal which can act as a promising candidate for mid-infrared lasers.

| S-EPMC4570185 | biostudies-other

Praseodymium Orthoniobate and Praseodymium Substituted Lanthanum Orthoniobate: Electrical and Structural Properties.

Project description:In this paper, the structural properties and the electrical conductivity of La1-xPrxNbO4+δ (x = 0.00, 0.05, 0.1, 0.15, 0.2, 0.3) and PrNbO4+δ are presented and discussed. All synthesized samples crystallized in a monoclinic structure with similar thermal expansion coefficients. The phase transition temperature between the monoclinic and tetragonal structure increases with increasing praseodymium content from 500 °C for undoped LaNbO4+δ to 700 °C for PrNbO4+δ. Thermogravimetry, along with X-ray photoelectron spectroscopy, confirmed a mixed 3+/4+ oxidation state of praseodymium. All studied materials, in humid air, exhibited mixed protonic, oxygen ionic and hole conductivity. The highest total conductivity was measured in dry air at 700 °C for PrNbO4+δ, and its value was 1.4 × 10-3 S/cm.

| S-EPMC8954274 | biostudies-literature

Synthesis, Thermal Analysis, Spectroscopic Properties, and Degradation Process of Tutton Salts Doped with AgNO3 or H3BO3.

Project description:In this work, we synthesized and studied the spectroscopic properties of (NH4)2(SO4)2Y(H2O)6 (Y = Ni, Mg) crystals doped with AgNO3 or H3BO3. These crystals constitute a series of hexahydrated salts known as Tutton salts. We investigated the influence of dopants on the vibrational modes of the tetrahedral ligands NH4 and SO4, octahedral complexes Mg(H2O)6 and Ni(H2O)6, and H2O molecules present in these crystals through Raman and infrared spectroscopies. We were able to identify bands that are attributed to the presence of Ag and B dopants, as well as band shifts caused by the presence of these dopants in the crystal lattice. A detailed study of the crystal degradation processes was performed by thermogravimetric measurements, where there was an increase in the initial temperature of crystal degradation due to the presence of dopants in the crystal lattice. Raman spectroscopy of the crystal residues after the thermogravimetric measurements helped us to elucidate the degradation processes occurring after the crystal pyrolysis process.

| S-EPMC10210023 | biostudies-literature

Single crystal growth, optical absorption and luminescence properties under VUV-UV synchrotron excitation of type III Pr3+:KGd(PO3)4.

Project description:Scintillator materials are widely used for a variety of applications such as high energy physics, astrophysics and medical imaging. Since the ideal scintillator does not exist, the search for scintillators with suitable properties for each application is of great interest. Here, Pr3+-doped KGd(PO3)4 bulk single crystals with monoclinic structure (space group: P21) are grown from high temperature solutions and their structural, thermal and optical properties are studied as possible candidates for scintillation material. The change in the unit cell parameters as a function of the Pr3+ level of doping and temperature is studied. Differential thermal analysis reveals that KGd0.942Pr0.058(PO3)4 is stable until 1140 K. The 5d3, 5d2 and 5d1 levels of Pr3+ with respect to the 3H4 ground state are centred at 166, 196 and 218 nm, respectively, in this host. The luminescence of KGd0.990Pr0.010(PO3)4, by exciting these 5d levels, shows intense emissions centred at 256 and 265 nm from the 5d1 to 3F3,4 and 1G4 levels of Pr3+ with a short decay time of 6 ns. The 6P3/2,5/2,7/2 → 8S7/2 transitions of Gd3+ appear after exciting the 5d levels of Pr3+ and the 4 f levels of Gd3+, showing an energy transfer between Pr3+ and Gd3+.

| S-EPMC7174386 | biostudies-literature