Zorica V Marinković Stanojević

• PhD
• University of Belgrade

Yttrium manganite (YMnO3) is widely investigated multiferroic material with potential use in many technological applications. In this paper, we report on the preparation and characterization of multiferroic hexagonal YMnO3 ceramics obtained by chemical synthesis route. Precursor powders were prepared by the polymerizable complex method from citrate...

In this paper, we present novel method for preparation of dual type mesoporous photoanodes with up to 5.0% of solar-to-current efficiency in dye-sensitized solar cells (DSSCs). The method includes sol–gel processing of titanium(IV)-isopropoxide with EDTA–Na2 and Triton X100, and hydrothermal treatment under autogeneous pressure of as prepared gels....

Bulk ceramic samples of BiFeO3 were light doped (up to 1%) with Nb⁵⁺ in the place of Fe³⁺ (B-site doping) and their multiferroic properties were investigated using XRD, SEM, polarization (PMTS) and magnetization (SQUID) techniques. It is shown that even the small percentages of doping can notably change electric and magnetic behavior. Electric cond...

Mesoporous TiO2 films with spherical architectures and promising performance in dye-sensitized solar cells (DSSCs) were prepared. The morphology of the films was investigated by scanning electron microscopy. Transmission electron microscopy analysis of the spheres disclosed the elongated shape of sub-20 nm primary particles, while BET analysis reve...

Dye-sensitized solar cells (DSSCs) are widely investigated 3rd generation photovoltaics on a verge of reaching the conversion efficiency of 15%. The core of a typical DSSC is its photoanode, consisting of mesoporous TiO2 layer deposited onto transparent conducting substrate, and sensitized with the light harvesting dye. In this paper, we propose no...

Dye-sensitized solar cells (DSSCs) are 3rd generation photovoltaic devices, which convert solar to electric power by utilization of photosensitive dye molecules anchored on the surface of highly porous titania (TiO2) thick film. In this work, we have compared the photovoltaic performance of DSSCs in which we have used titania films prepared from ei...

BiFeO3 powders were synthesized by sonochemically assisted hydrothermal and hydro-evaporation methods. The X-ray diffraction confirmed the presence of secondary phases, Bi25FeO39 and Bi2Fe4O9, in as prepared BiFeO3 powders. Optimization of sintering conditions indicated that temperature of 800 °C and time of 2 h after pressing at 9 t/cm2 provided c...

Bismuth ferrite, BiFeO3 (BFO), powder was synthesized by hydrothermal method from Bi(NO3)3•5H2O and Fe(NO3)3•9H2O as precursors. The synthesized powder was further sintered using spark plasma sintering (SPS). The sintering conditions were optimized in order to achieve high density, minimal amount of secondary phases and improved ferroelectric andma...

In this work single phase hexagonal YMnO3 powders were prepared starting from Y(CH3COO)3·xH2O, Mn(CH3COO)2·4H2O, KMnO4 and KOH using methods of conventional (280 °C for 6 h) or microwave assisted hydrothermal synthesis (200 °C for 2 h) followed by calcination at 1200 °C for 2 h. According to FESEM analysis the calcined powders consisted of submicro...

Previously synthesized nanocrystalline ZnO doped with cobalt and manganese, Bi2O3 and Sb2O3 were the precursors for high voltage varistors preparation. Varistor ceramics were sintered at 750 °C, 770 °C or 900 °C for 1 h. An amount of 30 mass% of secondary phases and sintering temperature of 770 °C were found to be optimal for obtaining varistor wit...

Dye-sensitized solar cells (DSSCs) are recognized as cost-effective alternative to the conventional solid state photovoltaic devices, and their conversion efficiencies are comparable figures to more expensive and commercialized amorphous-Si devices, CZTS (copper zinc tin sulphur), CIGS (copper indium gallium selenide) or the organic solar cells. Th...

We have combined sol-gel synthetic route with hydrothermal synthesis under autogenous pressure to obtain stable TiO2 precursor gels. The gels were mixed with organic functional additives into pastes, and deposited onto fluorine-doped tin oxide (FTO) conductive substrates (12-14 Ω/sq) using tape-casting film applicator. As deposited films were caref...

Nanostructured single layered (pure TiO2 , pure α-Fe2O3 and mixed Fe2O3 /TiO2 with two different oxide ratios, 2 : 3 and 3 : 2) and double layered (TiO2 layer over a Fe2O3 layer) thick films have been fabricated by screen printing technology on a glass substrate. The pastes used for film preparation were obtained by adding an organic vehicle to the...

Single-phase YMnO3, a multiferroic material, is synthesized for the first time by milling a mixture of Y2O3 and Mn2O3 in a planetary ball mill for 60—720 min.

A powder mixture of Bi2O3 and Fe2O3 was mechanically treated in a planetary ball mill in an air from 30 to 720 minutes. It was shown that the mechanochemical formation of BiFeO3 (BFO) phase was initiated after 60 min and its amount increased gradually with increasing milling time. A detailed XRPD structural analysis is realized by Rietveld’s struct...

Titanium(IV) oxide in the form of anatase has proven to be the best choice for photoanodic material in dye-sensitized solar cells (DSCs). The aim of the work was to study the influence of binder molecular weight on the morphology of deposited films, and consequently, DSC parameters. For this study, five different TiO2 tape casting slips were prepar...

Introduction Experimental Results and Disscusion Conclusion Acknowledgement

We have studied the formation of BiMnO3 (BMO) nanocrystalline perovskite powder produced by high-energy milling of the constituent oxides. The crystal structure and the amount of crystalline and amorphous phases in the powder as a function of the milling time were determined with XRPD using Rietveld refinement. BMO perovskite formed directly from h...

Multiferroic bismuth manganite (BiMnO3) is known as a material that exhibits both ferromagnetic and ferroelectric properties making it interesting for various technological applications. Unfortunately, preparation of BiMnO3 is not possible by a conventional solid-state reaction and it can form only from mixture of oxides at high pressures (>40kbar)...

In this article the solid state reaction of BaTiO3 formation from a mechanically activated BaCO3-TiO2 system has been investigated. An equimolar mixture of BaCO3 and TiO2 powders was activated in a planetary ball mill in a continual regime for 0, 30 and 90 min, pressed and thermally treated up to 1200oC. The effect of the milling and firing regime...

In this article the solid state reaction of BaTiO3 formation from a mechanically activated BaCO3-TiO2 system has been investigated. An equimolar mixture of BaCO3 and TiO2 powders was activated in a planetary ball mill in a continual regime for 0, 30 and 90 min, pressed and thermally treated up to 1200oC. The effect of the milling and firing regime...

The common nitrates precursor solution leading to the Y3Al5O12:Ce3+ (YAG:Ce) composition with 2at.% of cerium, is ultrasonically atomised and introduced into the tubular flow reactor at 320°C. Having in mind that extremely high heating rates and short residence time are associated with spray pyrolysis, the low temperature regime is used for aerosol...

A mixture of starting ZnO and Cr2O3 powders in equimolar quantities was mechanically activated by grinding using a high energy vibro-mill for 0, 40 and 80min. The spinel ZnCr2O4 was prepared from activated mixtures by a conventional solid-state reaction at the temperature of 900°C during 240min. Raman scattering (RS) and Far-infrared (IR) spectrosc...

The yttrium-aluminium garnet phase (YAG) represents a suitable host material for solidstate lasers and is widely used for various display applications being doped with rare-earth ions. Introduction of Ce3+ ion as a luminescence centre transforms it from insulating to effective phosphor material capable of emitting radiation in the visible spectrum....

The ferroelectric properties and leakage current mechanisms of preferred oriented Bi3.25La0.75Ti3O12 (BLT) thin films deposited on La0.5Sr0.5CoO3 (LSCO) by the polymeric precursor method were investigated. Atomic force microscopy indicates that the deposited films exhibit a dense microstructure with a rather smooth surface morphology. The improved...

An equimolar mixtures of starting ZnO and Cr2O3 powders were mechanically activated by grinding using a planetary ball mill for various periods of time (40–320 min). Formation of nanocrystalline ZnCr2O4 as normal spinel structure at room temperature is detected in all samples—after ball-milling.A detailed XRD structural analysis (the relative phase...

Pt/Ru-doped ZnO nanophase particles were synthesized using ultrasonic spray pyrolysis. Particles were obtained through decomposition of zinc nitrate and newly developed Pt(IV) and Ru(III) complexes. The particle morphology, phase composition and chemical structure were revealed in accordance to various analysis methods (XRD, DSC, SEM/EDS, TEM) and...

Pt/Ru-doped ZnO nanophase particles were synthesized using ultrasonic spray pyrolysis. Particles were obtained through decomposition of zinc nitrate and newly developed Pt(IV) and Ru(III) complexes. The particle morphology, phase composition and chemical structure were revealed in accordance to various analysis methods (XRD, DSC, SEWEDS, TEM) and d...

The aim of this work is the investigation of experimental conditions for mechanochemical synthesis of spinel zinc stannate (Zn2SnO4). Application of this material include manufacturing of CO, H2, NO, NO2, i-C4H10 and C2H5OH gas sensors, production of transparent conducting electrodes, window coatings and anode for use in photoelectrochemistry. Star...

Freeze-drying, as a cryochemical powder processing method is applied in the synthesis of ZnO submicrometer to nanosized powders. The process involves rapid freezing of the sprayed precursor solution, drying under vacuum by sublimation of the solvent and salt decomposition to oxide by thermal treatment.Calcination of dehydrated Zn(NO3)2 was performe...

Nanocomposite powders in the system (La1−xSrx)aMnO3-YSZ(1−y) [LSM-YSZ], as an attractive cathode material for high operating solid oxide fuel cell (SOFC), were obtained through ultrasonic spray pyrolysis (1.7MHz) method. The principle of the synthesis is based on a single-step high temperature aerosol decomposition of atomized precursor solutions c...

The nature of exothermal and irreversible structural changes observed during linear heating of nanocrystalline ZnO powders was investigated using differential scanning calorimetry, X-ray, SEM and TEM analysis. Nanocrystalline ZnO powders were obtained by ultrasonic spray pyrolysis of 0.8 mol/dm3 zinc nitrate solution and subsequent decomposition of...

Mixtures of starting ZnO and Cr2O3 powders in equimolar quantities were mechanically activated by grinding using a high energy vibro-mill for 0, 40 and 80 minutes. Qualitative X-ray diffraction analysis made after sintering at 900°C for 240 min showed the presence of a well-crystallized spinel-type phase, ZnCr2O4, in all examined samples. A detaile...

The synthesis of calcium titanate, CaTiO3, was performed by mechanical activation and thermal treatment. Milling for up to 360 minutes in a planetary ball mill mechanically activated an equimolar mixture of CaCO 3 and TiO2 powders. A small amount of mechanically activated mixtures was pressed into briquettes and calcined at 850°C for two hours. The...

Mixtures of starting ZnO and Cr2O3 powders in equimolar quantities were mechanically activated by grinding using a high energy vibro-mill for 0, 40 and 80 minutes. Qualitative X-ray diffraction analysis made after sintering at 900degreesC for 240 min showed the presence of a well-crystallized spinel-type phase, ZnCr2O4, in all examined samples. A d...

Polycrystalline tin oxide thin films were prepared from ethanol solution of SnCl2·H2O (concentrations: 0.05, 0.1, 0.2 and 0.4mol/dm3) at different substrate temperatures ranging from 300 to 450°C. The kinetic deposition processes were studied in terms of various process parameters. The crystal phases, crystalline structure, grain size and surface m...

It is well established that gas/humidity-sensing properties of spinels are markedly influenced by their stoichiometry and microstructure. In this work nucleation and spinel phase development in the Zn-Cr-O system were investigated from the viewpoint of structural and morphological phenomena occurred during nanophased particle synthesis through aero...

This paper represents the results of the design of functional nanocrystalline powders and nanocomposites using chemical reactions in aerosols. The process involves ultrasonic aerosol formation (mist generators with the resonant frequencies of 800 kHz, 1.7 and 2.5 MHz) from precursor salt solutions and control over the aerosol decomposition in a hig...

Phase transformations and thermal effects of BaTiO 3 ceramics due to influence of mechanical activation were investigated. Equimolar mixture of BaCO 3 and TiO 2 powders was activated in high energy vibromill for various grinding times. Specific surface area determinations of initial and activated powders were carried out. The phase composition and...

Among many aerosol routes, the Pyrosol process, due to its simplicity, low cost and quality of obtained films, represents a promising technique for the synthesis of thin films. The pyrosol process is based on the transport and pyrolysis of an aerosol of processor solution, generated in an ultrasonic atomizer, on a heated substrate. The theoretical...

Among many aerosol routes, the Pyrosol process, due to its simplicity, low cost and quality of obtained films, represents a promising technique for the synthesis of thin films. The pyrosol process is based on the transport and pyrolysls of an aerosol of processor solution, generated in an ultrasonic atomizer, on a heated substrate. The theoretical...

The thermal behavior of ZnO powder obtained by ultrasonic spray pyrolysis of nitrate solution (c=0.8mol/dm3, D0=2.695µm, Tmax=6000C, FG=1.2dm3/min) was investigated using non-isothermal differential scanning calorimetry (DSC, heating rates 5, 10, 15, 20O/min). The exothermic heat effects at the temperature range from 350 to 5000C were linked to par...

Ultrasonic spray pyrolysis (1.7 MHz) has been applied for the generation of zinc chromium oxide submicronic (470 nm) particles from the corresponding metal nitrate solution. Heterogeneous gas-liquid/solid chemical reactions occurred in dispersed systems (aerosols) at 1173 K with the residence time ranging from 3 to 6 s. Such a synthesis method enab...

The alumina/silica with zinc chloride aerogel alkylation catalyst was obtained using a one step sol-gel synthesis, and subsequent drying with supercritical carbon dioxide. The aerogel catalyst activity was found to be higher compared to the corresponding xerogel catalyst, as a result of the higher aerogel surface area, total pore volume and favoura...

High-purity submicron Bi–Pb–Sr–Ca–Cu–O particles were prepared by the freeze-drying method from modified aqueous solutions of the corresponding metal nitrates. Synthesis through an aerosol enables the generation of ultrafine multicomponent powders with improved compositional homogeneity. Bi–Pb–Sr–Ca–Cu–O rich particles obtained through freeze dryin...

The development of new methods for synthesis of advanced materials results in further improvement of their properties. In this paper freeze drying, a cryochemical method, is used for the synthesis of ZnO and Bi1.8Pb0.2Sr2Ca2Cu3Ox powders. ZnO and Bi1.8Pb0.2Sr2Ca2Cu3Ox powders were derived from 1M solution of Zn(NO3)2x6H2O, and 1M solutions of metal...

The properties of different ceramic functional materials are greatly influenced by the characteristics of the starting powders. With increasing demands for more reliable ceramics, there has been significant progress in research on powder synthesis methods with an accent on the attainment of closely controlled physical and chemical characteristics....

The formation of TiO2 prepared by hydrolysis method was presented. Thermodynamics and kinetics of anatase crystallization reaction were investigated. Differential method of kinetic data evaluation in non-isothermal conditions according toKissinger, Ozawa and Kazeev-Yerofeev was applied. Starting, crystallized and thermally treated powders were dete...

Mechanical activation of simple and complex powder systems is very often used as a method for modification of physico-chemical properties in technologies for obtaining advanced materials. The present work reports on investigation of cordierite formation from starting powders mixture of basic magnesium carbonate (BMC) and kaolinite. Starting powders...