WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7150
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Article Investigation of the Experimental and Theoretical Band Gap of Pbvo3cl for Use in Energy Conversion Devices(Pergamon-elsevier Science Ltd, 2024) Harmanli, Ipek; Aytekin, Ahmet; Gol, Emre Yusuf; Eanes, Mehtap; Karabudak, EnginThe major goal of the research described in this paper is to investigate the structure of electronic band and band gap of the novel semiconductor lead (II) trioxovanadate (V) chloride (PbVO3Cl). 3 Cl). Depending on both experimental and theoretical (computational) results, the utility of PbVO3Cl 3 Cl as a semiconductor in solar fuel devices was discussed. The optical band gap was determined experimentally by applying Tauc Plot method to the absorption spectra of PbVO3Cl. 3 Cl. Additionally, computational approaches for the structure prediction of PbVO3Cl 3 Cl have been studied. The electronic band structures were examined theoretically using local density (LDA), generalized gradient (GGA), and hybrid (HSE06) approximations. PbVO3Cl, 3 Cl, which has an optical band gap of about 2.2 eV, has been shown to have promising photocatalytic properties. As a result of these approximations, the transition type of PbVO3Cl 3 Cl was determined as indirect. We also discussed the potential future application of PbVO3Cl 3 Cl in Lewis solar fuel devices as a combination of the photoanode and Si photocathode. And the solar efficiency of the PbVO3Cl-Si 3 Cl-Si double-layer semiconductor system was calculated. Further experimental proofs can be important.Article Citation - WoS: 20Synthesis, Structural Characterization, and Magnetic Properties of Nare9(geo4)(6)o-2 (re=nd, Pr)(Elsevier Ltd., 2004) Eanes, Mehtap; Pennington, WT; Kolis, JWThe new compounds NaRE9(GeO4)(6)O-2 (RE = Nd, Pr) have been synthesized at 500 and 524 degreesC, respectively, via the hydrothermal method. The compounds crystallize with an oxyapatite structure in the hexagonal space group P6(3)/m with one formula unit in a cell of dimensions a = 9.782(1) Angstrom, c = 7.083(1) Angstrom (T = 293 K), V = 587.0(2) Angstrom(3) for RE = Nd and a = 9.802(1) Angstrom, c = 7.116(1) Angstrom (T = 293 K), V = 592.1(2) Angstrom(3) for RE = Pr. Each structure is composed of REO7 and REO9 polyhedra as well as GeO4 tetrahedra. The magnetic susceptibility data indicates paramagnetic behavior for both compounds at temperatures between 60-300 K for Nd and 2-300 K for Pr with a Weiss constant of theta = 44.8 and 33.5 K for Nd and Pr, respectively. (C) 2003 Elsevier B.V. All rights reserved.Article Citation - WoS: 31Citation - Scopus: 36Integration of Triboluminescent Eud4tea Crystals To Transparent Polymers: Impact Sensor Application(American Chemical Society, 2017) İncel, Anıl; Eanes, Mehtap; McMillen, Colin D.; Demir, Mustafa MuammerLanthanide-based organometallic materials are well-known candidate triboluminescent (TL) materials that can show bright emission when a mechanical force is applied. These materials are usually in the form of crystalline powders, and it is often useful to integrate these samples into a polymer matrix in order to achieve processability, enabling coating from a solution/molten state or fabrication as a complex-shaped matrix. In this work, micrometer-sized europium tetrakis (dibenzoylmethide) triethylammonium (EuD4TEA) crystals were synthesized and integrated with various transparent polymers (PMMA, PS, PVDF, and PU) using two approaches: (i) blending and (ii) surface impregnation. In the former method, the crystalline particles were molecularly dissolved; therefore, a TL response cannot be achieved. More than 10 wt % TL crystals in the composite is needed to obtain TL signals. However, TL signal was achieved at 2.5 wt % when a composite was prepared by the latter approach. TL intensity shows exponential decay with consecutive mechanical action. The TL emission of PU-based surface impregnated composite expires with long-lived emission, and maximum TL response with respect to applied force was measured between 2.45 and 42.0 N.Article Citation - WoS: 7Citation - Scopus: 7Hydrothermal Synthesis of New Rare Earth Silicate Fluorides: a Novel Class of Polar Materials(Academic Press Inc., 2012) McMillen, Colin D.; Eanes, Mehtap; Stritzinger, Jared T.; Kolis, Joseph K.Polar crystals provide an interesting avenue for materials research both in the structures they form and the properties they possess. This work describes the hydrothermal synthesis and structural characterization of three novel silicate fluorides. Compound (1), LiY 3(SiO 4) 2F 2 crystallizes in space group C2/c, with a=17.651(4) Å, b=4.8868(10) Å, c=11.625(2) Å and β=131.13(3)°. BaY 2(Si 2O 7)F 2 (2) crystallizes in space group P-1, with a=5.1576(10) Å, b=6.8389(14) Å, c=11.786(2) Å, α=93.02(3)°, β=102.05(3)° and γ=111.55(3) °. Finally, the structure of Ba 2Y 3(SiO 4) 2F 5 (3) was determined in the polar orthorhombic space group Pba2, having unit cell parameters a=8.8864(18) Å, b=12.764(3) Å and c=5.0843(10) Å. The structures are compared based on their building blocks and long range polarities. Aligned silicate tetrahedra segregated into a single layer in (3) impart the observed polarity.Article Citation - WoS: 4Citation - Scopus: 5Crystal Structure of Distrontium Manganese (iii) Tetraoxophosphate Heptaoxodiphosphate, Sr2mn[po4] [p2o 7](Walter de Gruyter GmbH, 2007) Doğan, Leyla; Eanes, MehtapMnO11P3Sr2, monoclinic, P121/c1 (no. 14), a = 6.641(1) Å, b = 6.834(1) Å, c = 19.554(4) Å, β = 99.22(3)°, V = 876.0 Å3, Z = 4, Rgt(F) = 0.051, wRref(F2) = 0.090, T = 298 K.Article Citation - WoS: 6Citation - Scopus: 6Crystal Structure of Lead(ii) Trioxovanadate(v) Chloride, Pb[vo 3]cl(Walter de Gruyter GmbH, 2007) Şahin, Aytaç; Eanes, MehtapClO3PbV, orthorhombic, Pnma (no. 62), a = 10.022(2) Å, b = 5.288(1) Å, c = 7.171(1) Å, V= 380.0 Å3, Z = 4, Rgt(F) = 0.035, wRref(F2) = 0.105, T= 153 K.Article Citation - WoS: 3Citation - Scopus: 5Hydrothermal Synthesis and Characterization of a New Layered Compound Li2vgeo5(Elsevier Ltd., 2004) Eanes, Mehtap; Kolis, Joseph W.The new compound Li2VGeO5 with a layered structure has been synthesized at 580°C via the hydrothermal method. The compound crystallizes in the space group P4/n of the tetragonal system with two formula units in a cell of dimensions a=6.5187(9)Å, c=4.5092(9)Å (T=298K), V=191.61(5)Å3. The structure is composed of layers made of repeating [(VO5)(GeO4)]1- units. Li+ ions reside between the layers. The magnetic susceptibility data show an antiferromagnetic coupling below 5K with C=0.47emuKmol-1, and θ=-13K with μeff=1.89μB for each Li 2VGeO5 unit.Article Citation - WoS: 11Citation - Scopus: 12Hydrothermal Synthesis, Characterization and Magnetic Properties of Navge2o6 and Livge2o6(Elsevier Ltd., 2004) Eanes, Mehtap; Kolis, Joseph W.Supercritical fluids are shown to be an excellent reaction media for the synthesis of novel solid state phases at intermediate temperatures. LiVGe 2O6 and NaVGe2O6 have the common pyroxene structure composed of VO6 linear chains. NaVGe 2O6 crystallizes in the monoclinic space group C2/c with four formula units having cell dimensions a = 9.960(4)Å, b = 8.853(10)Å, c = 5.4861(10)Å, β = 106.403(3)°. The structure was refined until R = 0.0290 and Rw = 0.0370. For LiVGe 2O6 in space group P21/c: a = 9.8508(7)Å, b = 8.754(3)Å, c = 5.3948(13)Å, β = 108(3)°, R = 0.0240 and Rw = 0.0250. The compounds contain edge-shared VO6 octahedral chains and corner-shared GeO4 tetrahedral chains. The presence of these VO6 chains results in spin-Peierls distortion. Structural and physical characterization of the compounds are reported.Article Citation - WoS: 2Citation - Scopus: 2Redetermination of the Crystal Structure of Sodium Trisamarium Digermanate Dihydroxide, Nasm3(geo4)2(oh)2(Walter de Gruyter GmbH, 2002) Eanes, MehtapGe2H2NaO10Sm3, monoclinic, C12/c1 (No. 15), a = 18.323(3)Å, b = 5.2369(8) Å, c = 12.108(2) Å, β= 131.230(2)°, V = 873.8 Å3, Z = 4, R gt(F) = 0.037, wRref(F2) = 0.010, T= 153 K.Article Citation - WoS: 5Citation - Scopus: 5Hydrothermal Synthesis and Characterization of One Dimensional Chain Structures of Monolacunary Keggin Polyoxoanions Substituted With Copper(Elsevier Ltd., 2015) Eanes, Mehtap; Önen, Banu; McMillen, Colin D.Two novel polymeric polyoxometallates constructed from transition metal substituted heteropolytungstates, [(4,4’bpyH2)2(4,4’bpyH)][PCuW11O39]·H2O (1), and [(4,4’bpyH2)(pyH)3][PCuW11O39]·2H2O (2), (4,4’bpy = 4,4’bipyridine, py = pyridine) have been synthesized under hydrothermal conditions and characterized by IR, TGA, single crystal X-ray diffraction and magnetic measurements. The product formation showed a high sensitivity toward experimental factors including pH and stirring. Compounds 1 crystallizes in the monoclinic space group P2(1)/n with a = 13.503(3) Å, b = 26.726(5) Å, c = 15.168(3) Å, = 99.61(3)° and Z=4. The second compound also crystallizes in space group P2(1)/n, but with a = 13.519(3) Å, b = 20.431(4) Å, c =18.655(4) Å, = 96.52(3)° and Z=4. Compound 1 exhibits a zigzag chain structure, while compound 2 exhibits a straight chain structure. Compound 2 is the first example of a polyoxometallate containing 1D chains of transitionmetal- substituted heteropolytungstate designed with two significantly different organic units as the countercations. The Cu2+ ions in 1 exhibit paramagnetic behavior.