A multidisciplinary approach to multiferroics

Multiferroics, materials where spontaneous long-range magnetic and dipolar orders coexist,represent an attractive class of compounds, which combine rich and fascinating fundamentalphysics with a technologically appealing potential for applications in the general area ofspintronics.Among the different types of multiferroic compounds, bismuth ferrite (BiFeO3 ; BFO) stands out because it is perhaps the only one being simultaneously magnetic and strongly ferroelectric at room temperature.BiFeO3 and Bi 1-x Ho x FeO3 ultrafine nanopowders were synthesized by the hydrothermal method. Here we use simple, low-cost and energy-saving hydrothermal method, which has advantages over the conventional methods. The influence of Ho doping on the crystal structure and magnetic properties of bismuth ferrite (BFO) nanopowders was investigated. The diffraction pattern was recorded at room temperature and atmospheric pressure in the absence of any re-heating of the sample. A fitting refinement procedure using the Rietveld method was performed which showed the incorporation of Ho3+ ions in the BiFeO3 crystal lattice, where they substitute Bi3+ ions. All the samples belong to R3c space group.In addition, theoretical investigation using bond valence calculations have been performed in order to mimic pure and Ho doped BiFeO3 compounds produced in the experiment. Various BFOpolymorphs were investigated as function of holmium concentration and final optimization of crystal structures has been performed on ab initio level using Density Functional Theory (DFT).Furthermore, electronic and magnetic properties of BiFeO3 were investigated using combination of experimental and theoretical methods. Magnetic behavior of synthesized materials was investigated by SQUIDmagnetometer in wide temperature interval (2-800 K). Splitting between the zero- field-cooled and field-cooled magnetization curves becomes more pronounced as the Ho concentration is increased, pointing to the development of weak ferromagnetic moment, which is usually connected with uncompensated spins or spin canting. Hysteresis loops show the same fact, attaining higher magnetization with more Ho included,andbecomingwider, i.e. magnetically harder.IX Serbian Ceramic Society Conference - Advanced Ceramics and Application : new frontiers in multifunctional material science and processing : program and the book of abstracts; September 20-21, 2021; Belgrad

Synthesis, structural, magnetic and optical properties of (Bi1-xHox)-ferrites

Magnetoelectric multiferroics, due to simultaneous ferroelectric and ferromagnetic ordering, have attracted wide attention in recent years, offering a wide range of potential applications in data storage media, spintronics and multi-state memories [1]. One of the wellknown materials exhibiting such properties is bismuth ferrite (BFO) BiFeO3. Because of the technological progress in the direction of nanotechnologies our interest is to obtain this compound in a form of nanoparticles. Since those particles are thermodynamically stable only in a very narrow temperature interval, the main challenge is to obtain a high-quality, uniform, single-phase material. Here we report the hydrothermal synthesis of BFO and Bi1-xHoxFeO3 ultrafine nanopowders, with a diameter of ~ 300 nm with no tendency to agglomerate. The diffraction patterns show that all obtained particles belong to the R3c space group. Regularity of the particle’s geometric shape was demonstrated by Scanning electron microscopy (SEM), while the high-resolution transmission electron microscopy (HRTEM) reveals an excellent crystallization with non-fragmented surfaces. Individual grain analysis confirmed the existence of an ultra-fine crystal structure, with an interplane distance of 0.297 nm (d = 0.297 nm), which corresponds to (012) crystal planes. Magnetometry revealed a magnetic phase transition at TN= 220 K, from a paramagnetic to canted antiferromagnetic phase. Doping with Ho increased the value of magnetization showing that weak ferromagnetic moment grows with the introduced defects, originating from the non-compensated magnetic moments due to the distortions of both the spin-cycloid order and the super-exchange bridges. Both distortions promote the additional spin-canting and increase the magnetization. The optical properties of the material were examined by the spectroscopic ellipsometry method and the energy gap was found to be 2.71 eV. Using the structure prediction method, which is based on the bond valence calculations, 11 additional perovskite-related structure candidates in different space groups were obtained, including a novel tetragonal BiFeO3 phase which has never been reported before. With this, we have demonstrated that the hydrothermal method has good potential in obtaining BFO, for achieving better properties for the multiferroic application and offers an overall conclusion that the local magnetic properties of nanoparticles mainly depend on the particle size and their diverse morphology due to the different preparation methods and annealing temperatures

Synthesis and caracterization of bismuth-ferrite nanoparticles (BiFeO3)

Bizmut ferit pripada grupi multiferoičnih materijala koji pokazuju feromagnetna i feroelektrična svojstva na sobnoj temperaturi, što otvara mogućnost njihove tehnološke primene...Bismuth ferrite belongs to a group of multiferoids that exhibit both ferromagnetic and ferroelectric properties at room temperature, which opens the possibility of its technological application..

Modeling the flow of fresh and deep frozen calibrated fruit by rotating sizing machines

Princip rada rotirajućih diskosnih kalibratora zasniva se na odvajanju plodova različitih geometrijskih karakteristika kroz zazore odgovarajućih dimenzija karakterističnih za svaku zadatu klasu posebno. Klase su raspoređene od najmanje do najveće u smeru rotacije diska, a lučna kalibraciona pregrada može biti dvojake izvedbe, sa konstantno opadajućom širinom zazora i sa kaskadnom širinom. U ovom radu se razmatra kretanje plodova sa aspekta njihove brzine, i analizira model za određivanje kapaciteta rotacionih diskosnih kalibratora za različite vrste svežeg voća kao i za duboko zamrznutu malinu. Maseni protoci odnosno kapaciteti kalibratora za ispitane vrste voća u radu su približni onim koji su dobijeni nekim drugim poznatim metodama. Maseni protok kalibriranog voća srazmeran je masi i obrnuto srazmeran prečniku plodova za tretirano voće.The principle of rotating sizing machines based on a division of the fruits of various geometrical characteristics of the gaps of the same dimensions are typical for any given class separately. The classes are deployed from the smallest to the largest in the direction of rotation of the disk, and arc sizing board can be mixed performance, as slope metering gape and step metering gape. This paper discusses the movement of fruit in relation of their speed, and analyzes the model for determining the capacity of rotating sizing machines for different kinds of fresh fruit and deep-frozen raspberries. Mass flow calibrator or capacity for fruits tested in this paper are similar to those obtained in some other known methods. Calibrated mass flow is proportional to the weight of fruit and fruit in inverse proportion to the diameter of treated fruit

Modeling the flow of fresh and deep frozen calibrated fruit by rotating sizing machines

Princip rada rotirajućih diskosnih kalibratora zasniva se na odvajanju plodova različitih geometrijskih karakteristika kroz zazore odgovarajućih dimenzija karakterističnih za svaku zadatu klasu posebno. Klase su raspoređene od najmanje do najveće u smeru rotacije diska, a lučna kalibraciona pregrada može biti dvojake izvedbe, sa konstantno opadajućom širinom zazora i sa kaskadnom širinom. U ovom radu se razmatra kretanje plodova sa aspekta njihove brzine, i analizira model za određivanje kapaciteta rotacionih diskosnih kalibratora za različite vrste svežeg voća kao i za duboko zamrznutu malinu. Maseni protoci odnosno kapaciteti kalibratora za ispitane vrste voća u radu su približni onim koji su dobijeni nekim drugim poznatim metodama. Maseni protok kalibriranog voća srazmeran je masi i obrnuto srazmeran prečniku plodova za tretirano voće.The principle of rotating sizing machines based on a division of the fruits of various geometrical characteristics of the gaps of the same dimensions are typical for any given class separately. The classes are deployed from the smallest to the largest in the direction of rotation of the disk, and arc sizing board can be mixed performance, as slope metering gape and step metering gape. This paper discusses the movement of fruit in relation of their speed, and analyzes the model for determining the capacity of rotating sizing machines for different kinds of fresh fruit and deep-frozen raspberries. Mass flow calibrator or capacity for fruits tested in this paper are similar to those obtained in some other known methods. Calibrated mass flow is proportional to the weight of fruit and fruit in inverse proportion to the diameter of treated fruit

Heavily vanadium-doped LiFePO4 olivine as electrode material for Li-ion aqueous rechargeable batteries

Since LiFePO4 batteries play a major role in the transition to safe, more affordable and sustainable energy production, numerous strategies have been applied to modify LFP cathode, with the aim of improving its electrochemistry. In this contribution, a highly vanadium-doped LiFe0.9V0.1PO4/C composite (LFP/C-10V) is synthesized using the glycine combustion method and characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Thermogravimetry Differential Thermal Analysis (TGDTA) and Cyclic Voltammetry (CV). It is shown that 10wt.% of vanadium can substitute Fe positions, thus decreasing unit cell volume, which is followed by generation of Li3V2PO4 traces, as detected by CV. High vanadium doping does not change the carbon content in the composite (≈ 13 wt.%) but improves its electronic conductivity and electrochemical performance in both aqueous and organic electrolytes. The reversibility and current response are increasing following the trend: LFP/C, LFP/C -3mol%V, LFP/C - 5mol % and LFP/C-10 mol %. The best specific capacity is obtained for the most highly doped olivine, which exhibits a reversible process at 1 mV s-1 in an aqueous electrolyte, thus showing a peak-to-peak distance of 56 mV. The high capacity of LFPC-10V is measured in both LiNO3 and NaNO3 electrolytes amounting to around 100 mAh g-1 at 20 mV s-1. Still, the material is only stable in LiNO3 electrolyte, making it more suitable for Li than Na-ion aqueous rechargeable batteries

Modeling the flow of fresh and deep frozen calibrated fruit by rotating sizing machines

Princip rada rotirajućih diskosnih kalibratora zasniva se na odvajanju plodova različitih geometrijskih karakteristika kroz zazore odgovarajućih dimenzija karakterističnih za svaku zadatu klasu posebno. Klase su raspoređene od najmanje do najveće u smeru rotacije diska, a lučna kalibraciona pregrada može biti dvojake izvedbe, sa konstantno opadajućom širinom zazora i sa kaskadnom širinom. U ovom radu se razmatra kretanje plodova sa aspekta njihove brzine, i analizira model za određivanje kapaciteta rotacionih diskosnih kalibratora za različite vrste svežeg voća kao i za duboko zamrznutu malinu. Maseni protoci odnosno kapaciteti kalibratora za ispitane vrste voća u radu su približni onim koji su dobijeni nekim drugim poznatim metodama. Maseni protok kalibriranog voća srazmeran je masi i obrnuto srazmeran prečniku plodova za tretirano voće.The principle of rotating sizing machines based on a division of the fruits of various geometrical characteristics of the gaps of the same dimensions are typical for any given class separately. The classes are deployed from the smallest to the largest in the direction of rotation of the disk, and arc sizing board can be mixed performance, as slope metering gape and step metering gape. This paper discusses the movement of fruit in relation of their speed, and analyzes the model for determining the capacity of rotating sizing machines for different kinds of fresh fruit and deep-frozen raspberries. Mass flow calibrator or capacity for fruits tested in this paper are similar to those obtained in some other known methods. Calibrated mass flow is proportional to the weight of fruit and fruit in inverse proportion to the diameter of treated fruit

Modeling the flow of fresh and deep frozen calibrated fruit by rotating sizing machines

Princip rada rotirajućih diskosnih kalibratora zasniva se na odvajanju plodova različitih geometrijskih karakteristika kroz zazore odgovarajućih dimenzija karakterističnih za svaku zadatu klasu posebno. Klase su raspoređene od najmanje do najveće u smeru rotacije diska, a lučna kalibraciona pregrada može biti dvojake izvedbe, sa konstantno opadajućom širinom zazora i sa kaskadnom širinom. U ovom radu se razmatra kretanje plodova sa aspekta njihove brzine, i analizira model za određivanje kapaciteta rotacionih diskosnih kalibratora za različite vrste svežeg voća kao i za duboko zamrznutu malinu. Maseni protoci odnosno kapaciteti kalibratora za ispitane vrste voća u radu su približni onim koji su dobijeni nekim drugim poznatim metodama. Maseni protok kalibriranog voća srazmeran je masi i obrnuto srazmeran prečniku plodova za tretirano voće.The principle of rotating sizing machines based on a division of the fruits of various geometrical characteristics of the gaps of the same dimensions are typical for any given class separately. The classes are deployed from the smallest to the largest in the direction of rotation of the disk, and arc sizing board can be mixed performance, as slope metering gape and step metering gape. This paper discusses the movement of fruit in relation of their speed, and analyzes the model for determining the capacity of rotating sizing machines for different kinds of fresh fruit and deep-frozen raspberries. Mass flow calibrator or capacity for fruits tested in this paper are similar to those obtained in some other known methods. Calibrated mass flow is proportional to the weight of fruit and fruit in inverse proportion to the diameter of treated fruit

Fruit Wine and Its Biologically Active Compounds’ Ability in Health Prevention

Background and objectives: Blackberry is one of the most important berry fruits growing in Serbia. Crops and derived products are rich sources of many natural active compounds, which possess beneficial health effects. In particular, it is possible to point out the role of blackberry and its derived products in hyperglycemia prevention since it is a very common problem among the general population today. Blackberry wine is a product which could have significant beneficial health effects during moderate consumption. The aim of this study was to investigate the α-glucosidase inhibitory activity of blackberry wine and the contribution of some natural compounds to this activity. Methods: Fruit wines were produced through microvinification during controlled fermentation by using pure yeast strain culture. Samples were lyophilized and dissolved in DMSO. The inhibition of α-glucosidase was evaluated by using α-glucosidase and substrate solution, p-nitrophenyl α-Dglucopyranoside. The identification and quantification of some natural compounds was conducted by using UPLC TQ-MS/MS. Results: After lyophilization of the produced blackberry wine, all of the determinations were conducted in four samples. The results for the α-glucosidase inhibitory activity were in the range of 31.5–55.7 µg/mL. The control showed acarbose whit inhibitory activity of 75.3 µg/mL. Moreover, the estimated amount of epicatehin, catehin, chlorogenic, ellagic, and gallic acids and their contribution to the α-glucosidase inhibitory activity of the sample was from 1.7% to 7.7%. Discussion: The obtained results show that blackberry wine is a good inhibitor of α-glucosidase compared to acarbose. The presence of phenolic compounds in wine is due to its extraction from the skin and seeds of blackberry during alcoholic fermentation. Ethanol, which naturally occurs in wine, has a key role in this process. Fruit wine can be considered as a potential functional food. α-glucosidase activity depends on the synergistic and antagonistic effect of natural active compounds in fruit wine.14th European Nutrition Conference : November 14-17, 2023, Belgrade