E. Antonelli, M. Andreeta, E. Botero, A. Hernandes
{"title":"Thick Film Laser Sintering: An Evidence for Two-step Process","authors":"E. Antonelli, M. Andreeta, E. Botero, A. Hernandes","doi":"10.2174/1874846501306010001","DOIUrl":"https://doi.org/10.2174/1874846501306010001","url":null,"abstract":"The results for the sintering of Bi4Ti3O12 (BIT)-doped BaTi0.85Zr0.15O3 (BTZ) thick films, deposited by electro- phoresis, using as heating source a CO2 laser are presented. The thermal process associated to the laser scanning sintering (LSS) acted in a similar way as a two-step-sintering process. This characteristic together with the high heating rate al- lowed us to obtain thick films with an average grain size of 200 nm, high relative density (~96%) and with a homogene- ous microstructure. The X ray diffraction profile analysis show evidences for Bi 3+ replacing Ba 2+ at the A sites.","PeriodicalId":23072,"journal":{"name":"The Open Crystallography Journal","volume":"1 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2013-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85983851","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
V. Bredikhin, G. Galushkina, P. KuznetsovStanislav
{"title":"Light Scattering in KDP Crystals and Relaxation Oscillations of Diffusion Layer in Crystal Growth from Solutions","authors":"V. Bredikhin, G. Galushkina, P. KuznetsovStanislav","doi":"10.2174/1874846501205010001","DOIUrl":"https://doi.org/10.2174/1874846501205010001","url":null,"abstract":"The problem of achieving high optical quality of crystals (KDP monocrystals in particular) grown from solutions under conditions of periodic feeding is considered. The experimental data obtained for rapid profiled growth of KDP crystals have demonstrated a pronounced dependence of crystal quality (light scattering) on feeding parameters: period and duty cycle of feeding, feeder height above the growing surface, and feeding intensity. The theoretical analysis has shown that these effects can be explained within the framework of diffusion layer relaxation at periodic feeding in the diffusion-kinetic regime of crystal growth.","PeriodicalId":23072,"journal":{"name":"The Open Crystallography Journal","volume":"12 1","pages":"1-7"},"PeriodicalIF":0.0,"publicationDate":"2012-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75528440","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Pandey, R. Dhar, A. S. Achalkumar, C. Yelamaggad
{"title":"Electrical Behaviour of Twist Grain Boundary Phases of 4-n-dodecyloxy- 4'-(cholesteryloxycarbonyl-1-butyloxy) chalcone","authors":"A. Pandey, R. Dhar, A. S. Achalkumar, C. Yelamaggad","doi":"10.2174/1874846501104010049","DOIUrl":"https://doi.org/10.2174/1874846501104010049","url":null,"abstract":"There are only few compounds, which have shown wide temperature range twist grain boundary (TGB) phases. One such compound is the cholesterol derived, 4-n-dodecyloxy-4'-(cholesteryloxycarbonyl-1-butyloxy) chalcone, which shows a wide temperature range TGBA (~ 11 °C) and TGBC * (~ 19 °C). In the present work, we are reporting the temperature and frequency dependence of the dielectric parameters of the above compound for two different conditions of molecular anchoring i.e. planar and homeotropic. The dielectric studies have been carried out in the frequency range of 1 Hz to 35 MHz. In homeotropically aligned sample, the experimental dielectric spectra display a feeble relaxation mode in TGBA and TGBC * phases in MHz frequency range. Planar oriented molecules show a soft mode like relaxation due to the tilt fluctuation of molecules in MHz region for both the TGB phases and support theoretical formulation for the soft mode relaxation of the TGB phases. Various dielectric parameters have been determined for the two TGB phases of the above mentioned compound.","PeriodicalId":23072,"journal":{"name":"The Open Crystallography Journal","volume":"36 1","pages":"49-58"},"PeriodicalIF":0.0,"publicationDate":"2011-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78997772","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rohit Vermaa, R. Dhar, R. Dabrowski, M. Rath, S. Sarkar
{"title":"Effect of Electron Irradiation on the Thermodynamical and Optical Properties of Cholesteryl Pelargonate","authors":"Rohit Vermaa, R. Dhar, R. Dabrowski, M. Rath, S. Sarkar","doi":"10.2174/1874846501104010040","DOIUrl":"https://doi.org/10.2174/1874846501104010040","url":null,"abstract":"Thermodynamical and optical properties of pure and electron beam irradiated (20, 80 and 100 kGy doses) liquid crystalline material cholesteryl pelargonate (nonanoate) have been investigated by differential scanning calorimeter, polarized light microscopy and ultraviolet-visible spectroscopy. Transition temperatures, enthalpies and entropies are found to be lowered due to the irradiation. A donor-acceptor type charge transfer complex peak is observed besides the pure sample peak in the ultraviolet-visible spectra due to irradiation. The concentrations of impurities have been estimated by the area of the pure and charge transfer complex peaks besides using the Van't Hoff equation. The concentration of impurity is found to increase linearly with the irradiation dose.","PeriodicalId":23072,"journal":{"name":"The Open Crystallography Journal","volume":"1 1","pages":"40-48"},"PeriodicalIF":0.0,"publicationDate":"2011-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89199254","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Two New Supramolecular Compounds that Involve Trans-1,2-bis(4-pyridyl)ethylene (bpe), Barbituric Acid and Fe(II) ions","authors":"H. Garcia, R. Diniz, L. C. Oliveira","doi":"10.2174/1874846501104010030","DOIUrl":"https://doi.org/10.2174/1874846501104010030","url":null,"abstract":"In this study, the synthesis, spectroscopic properties (infrared and Raman) and crystal structures of two new compounds named (H2bpe)B2 . 2H2O (1) and (Fe(bpe)(H2O)4)B2·4H2O (2) have been reported, where bpe is trans-1,2- bis(4-pyridil)-ethylene, H2bpe is protonated bpe and B - is the barbiturate anion. For both complexes, we observed the presence of supramolecular interactions, such as electrostatic, hydrogen bonding and � -stacking interactions. Compound 1 crystallised in a triclinic system with the space group P-1, which was generated by cationic and anionic units formed by protonated bpe, the barbiturate anion and water molecules. These molecules interacted through weak intermolecular inter- actions and were responsible for the crystalline stability of the synthesised compounds. For compound 2, an orthorhombic crystal system was observed with a Pbcn space group. In this crystal, the metallic site adopted a distorted octahedral ge- ometry that was coordinated by two pyridine nitrogen atoms and four oxygen atoms from coordinated water molecules. The three-dimensional arrangement of the structure consisted of one covalent one-dimensional linear cationic (Fe(bpe)(H2O)4) 2+ chain, which interacts by forming hydrogen-bonding, � -stacking and electrostatic interactions with bar- biturate anions and water molecules that were trapped in the crystal. The vibrational spectra of the two compounds were very similar despite the different crystalline arrangements that were adopted by the two structures. In the infrared spectra, two intense bands at 1684 and 1630 cm -1 were observed and assigned to the CO stretching ( CO) of the barbiturate anion and C=C of the bpe ligand, respectively. In the Raman spectra of the compounds, the most important bands were attrib- uted to the bpe ligand at 1629 and 1006 cm -1 , which were assigned to the C=C and ring, respectively. The presence of the barbiturate anion was confirmed by the presence of a band of low intensity located at 680 cm -1 and was assigned as the","PeriodicalId":23072,"journal":{"name":"The Open Crystallography Journal","volume":"77 1","pages":"30-39"},"PeriodicalIF":0.0,"publicationDate":"2011-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90568420","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Novel Thermally-Accessible Structural Distortion and Lattice Strain of a Chiral Cyanide-Bridged Cu (II)-Ni (II) Complex","authors":"Yusuke Kimoto","doi":"10.2174/1874846501104010021","DOIUrl":"https://doi.org/10.2174/1874846501104010021","url":null,"abstract":"We have investigated temperature dependence of crystal structure of a chiral cyanide-bridged bimetallic assembly of [CuL2][Ni(CN)4]·2H2O (1) (L = (1R, 2R)-diaminocyclohexane). Cell parameters and most of bond distances decreased on cooling for 1. However, only a long Cu-N bond of semi-coordination increases on cooling, which is the first example of negative thermal elongation of specific bond distances.","PeriodicalId":23072,"journal":{"name":"The Open Crystallography Journal","volume":"12 1","pages":"21-24"},"PeriodicalIF":0.0,"publicationDate":"2011-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74304008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Isotope Effect and Lanthanide Contraction for 3d-4f Cyanide-Bridged Complexes Exhibiting Negative Thermal Expansion","authors":"Yusuke Kimoto, Takeshi Matsui, T. Akitsu","doi":"10.2174/1874846501104010016","DOIUrl":"https://doi.org/10.2174/1874846501104010016","url":null,"abstract":"We have prepared some 3d-4f cyanide-bridged Ln(DMF)4(H2O)3Fe(CN)6•H2O complexes (Ln = Ce, Sm, Nd, and Gd; DMF = N,N-dimethylformamide) by substituting isotopes to 2 H-substituted H2O and DMF and 18 O-substituted H2O (and normal 1 H- and 16 O-H2O or 1 H-DMF). We examined their crystal structures exhibiting negative thermal expansion and compared in view of hydrogen bonds and lanthanide contraction. Magnetic properties and thermal analysis exhibited importance of intermolecular hydrogen bonds in crystal lattice for this behavior. While Fe2p3/2 and Fe2p1/2 XAS indicated constant inner shell electron states of low-spin Fe(III) ions.","PeriodicalId":23072,"journal":{"name":"The Open Crystallography Journal","volume":"34 1","pages":"16-20"},"PeriodicalIF":0.0,"publicationDate":"2011-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78847314","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Akitsu, M. Ohwa, Yukihiko Endo, Satoru Sonoki, Y. Aritake, Yusuke Kimoto
{"title":"Some Factors and Effects on Thermally Structural Changes of Lattice for Cyanide-Bridged Bimetallic Assemblies of Cu(II)","authors":"T. Akitsu, M. Ohwa, Yukihiko Endo, Satoru Sonoki, Y. Aritake, Yusuke Kimoto","doi":"10.2174/1874846501104010025","DOIUrl":"https://doi.org/10.2174/1874846501104010025","url":null,"abstract":"In order to understand novel structural features of crystal packing of [CuL2][Ni(CN)4]·2H2O (L = (1R,2R)-1,2diaminocyclohexane), we have investigated temperature effect, metal-size effect, and isotope effect and their temperature dependence (100-300 K) with synchrotron powder X-ray diffraction (XRD) for (1) [CuL2][M(CN)4]·2H2O (M=Pd, Pt), (2) [CuL’2][M(CN)4] (M=Ni, Pd, and Pt; L’ = N-ethylethylenediamine), and (3) [CuL’’2][M(CN)6]·nH2O (L’’ =(1S,2S)-1,2dimethylcyclohexanediamine. M=Cr, Co, and Fe; isotopes of H2O are H(H), H(D), and O(O), respectively). The effect of the factors of (1) (temperature difference of 200 K) is comparable to metal size for the system of (1). Combinatorial preparation of (2) gave rise to the most stable Pd(II) complexes predominantly. Isotope effect of water molecules resulted in little structural changes of lattice for (3).","PeriodicalId":23072,"journal":{"name":"The Open Crystallography Journal","volume":"529 1","pages":"25-29"},"PeriodicalIF":0.0,"publicationDate":"2011-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80159946","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Isotope Effects for Lattice Strain and Pseudo Jahn-Teller Distortion of Chiral Cyanide-Bridged Cu(II)-Co(III), Cr(III), and Fe(III) Bimetallic Assemblies","authors":"T. Akitsu, Satoru Sonoki","doi":"10.2174/1874846501104010008","DOIUrl":"https://doi.org/10.2174/1874846501104010008","url":null,"abstract":"By substituting H/D and 18 O isotopes of water molecules, we prepared co-crystals of one-dimensional cyanide- bridged Cu(II)-Cr(III), Cu(II)-Co(III), and Cu(II)-Fe(III) bimetallic assemblies and mononuclear Cu(II) complexes, (CuL2)3(M(CN)6)2·4H2O (L = trans-cyclohexane-(1R, 2R)-diamine; M = Cr, Co, and Fe). Solid state CD and diffuse re- flectance electronic spectra exhibited typical difference of metal ions and little isotope effects. While H/D isotope effects emerged as differences of small intermolecular magnetic interactions and obvious shifts of IR bands. Though all com- pounds exhibited positive thermal expansion of lattice, crystal structures exhibited slight differences associated with Jahn- Teller distortion around Cu(II) coordination environment.","PeriodicalId":23072,"journal":{"name":"The Open Crystallography Journal","volume":"5 1","pages":"8-15"},"PeriodicalIF":0.0,"publicationDate":"2011-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89917748","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Akitsu, Yukihiko Endo, Minoru Okawara, Yusuke Kimoto, M. Ohwa
{"title":"Influence of Water Molecules on Properties of Binuclear or Bridged Structures for Chiral CuII-NiII, CuII-PdII, and CuII-PtII Tetracyano- Bimetallic Assemblies","authors":"T. Akitsu, Yukihiko Endo, Minoru Okawara, Yusuke Kimoto, M. Ohwa","doi":"10.2174/1874846501104010002","DOIUrl":"https://doi.org/10.2174/1874846501104010002","url":null,"abstract":"We have prepared new chiral bimetallic assemblies of discrete binuclear [CuL2][Ni(CN)4]·2H2O or onedimensional cyanide-bridged [CuL2][Pd(CN)4] (and [CuL2][Pt(CN)4]) (L = (1S,2S)-(+)-N,N'-dimethyl-cyclohexane-1,2diamine). The numbers of co-crystallized water molecules contained are different from each other and their compositions are easy to vary due to co-crystallized water molecules. As far as we studied on the related [Cu(diamine)2]a [M(CN)b]c·dH2O compounds, actually such a feature has been found for the first time. According to crystal structures, the elongated axial bond distances of [CuL2] 2+ moieties are Cu-N = 2.195(7) Å for [CuL2][Ni(CN)4]·2H2O, Cu-N = 2.443(4) and 2.519(2) Å for [CuL2][Pd(CN)4]. Single crystal structure analyses, variable low temperature XRD, measurements of electronic, CD, emission, and XPS spectra and magnetic properties have been carried out. We compared their structural preference between Ni and Pd (or Pt) metal ions. Novel emission band of [CuL2][Pt(CN)4] appeared at 410 nm ( ex = 360 nm) in the solid state regardless of quenching by cyanide-bridged [CuL2] 2+ moieties.","PeriodicalId":23072,"journal":{"name":"The Open Crystallography Journal","volume":"46 1","pages":"2-7"},"PeriodicalIF":0.0,"publicationDate":"2011-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90998497","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}