Wyniki wyszukiwania - Biblioteka Nauki

1

Structural Characterization and Properties of Al/Fe Multi-Layer Composites Produced by Hot Pressing

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Kowalski W. , Paul H. , Mania I. , Petrzak P. , Czaja P. , Chulist R. , Góral A. , Szlezynger M.

Archives of Metallurgy and Materials

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2023

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tom Vol. 68, iss. 1

137--144

EN

This study aimed to develop Fe/Al multilayered metallic/intermetallic composites produced by hot pressing under an air atmosphere. Analyses were carried out on the composite plates made up of alternatively situated sheets of AA1050 aluminum alloy and DN04 low carbon steel, which were annealed at 903 K for 2, 5, and 10 h. Annealing was performed to obtain reaction layers of distinct thickness. The samples were examined using X-Ray diffraction and scanning and transmission electron microscope equipped with an energy-dispersive X-Ray spectrometer. To correlate the structural changes with mechanical properties, microhardness measurements in near-the-interface layers were performed. All the reaction layers grew with parabolic kinetics with η-Al5Fe2 intermetallic phase as the dominant component. After annealing for 5 and 10 hours, a thin sublayer of θ-Al13Fe4 phase was also detected.

2

Processing and microwave dielectric properties of Sr5Ta4TiO17 ceramics

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Manan A. , Ahmad A. S. , Ullah A. , Shah A. A.

Materials Science Poland

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2017

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tom Vol. 35, No. 4

767--772

EN

Sr5Ta4TiO17 ceramics was processed via solid state mixed oxide sintering route. X-ray diffraction revealed single phase formation of Sr5Ta4TiO17 ceramics that crystallized into an orthorhombic crystal structure with a space group Pnnm with lattice parameters of a = 5.681 Å, b = 32.542 Å and c = 3.968 Å, refined by the least squares method. The unit cell density (ρth) was 6.71 g/cm3. The microstructure consisted of plate-like grains and the average size was increased from 2 µm to 5 µm with an increase in sintering temperature from 1450 °C to 1575 °C. Optimum microwave dielectric properties, i.e. єr ~ 66, Qufo ~ 8500 GHz and τf ~ 180 ppm/°C, were achieved for Sr5TaTiO17 ceramics sintered at 1550 °C for 4 h.

3

Effect of upgraded field assisted sintering technology on microstructure of NiAl/CrB2 composites

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Szlezynger M. , Maj Ł. , Pomorska M. , Morgiel J. , Jach K. , Rosinski M.

Composites Theory and Practice

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2020

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tom R. 20, nr 1

7--10

EN

The method of fabricating metal matrix composites plays a crucial role in obtaining dense materials characterized by high wear resistance. The present work describes an attempt to produce NiAl/CrB2 composites using the next generation spark plasma sintering (SPS) method, i.e. upgraded field assisted sintering technology (U-FAST) technique. Microstructure characterization was performed by means of scanning (SEM) and transmission (TEM) electron microscopy. The SEM microstructure investigations of the NiAl model material proved practically full densification of the material sintered at 1200°C and 1300°C, even if remnants of surplus nickel were observed at the boundaries of rounded NiAl grains. The NiAl/CrB2 composites, besides fused NiAl and CrB2 grains, showed the presence of a raised level of nickel also at the grain boundaries. The TEM microstructure observations helped to establish that even if the grain boundaries were pinned by nickel-rich precipitates, some increase in grain growth took place, as evidenced by the fact that strings of smaller precipitates were also visible outside the matrix grain boundaries. All these microstructure investigations indicate that the newly elaborated U-FAST technique is evidently capable of producing compacts free of porosity at lower temperatures and during a shorter time than solid hot pressing or vacuum sintering in a semiliquid state.

4

The method of electron microscopic study of Corti organ in guinea pig

100%

Olszewski J.

Folia Morphologica

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1989

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tom 48

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nr 1-4

5

Effect of growth time on the morphologies of vapour grown carbon fibres and a suggested mechanism of growth

100%

Zhang H. , Shi J. , Song Y. , Zhao J. , Wang K. , Guo Q. , Zhai G. , Liu L.

Materials Science Poland

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2009

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tom Vol. 27, No. 3

885--890

EN

The microstructure of vapour grown carbon fibres is two-double layered. This paper addresses the question of morphology transformation of vapour grown carbon fibres. Special attention is given to developing understanding of the growth mechanism of the outer layer of the fibres. The influence of growth time on the morphologies of as-prepared carbon fibres was investigated using scanning electron microscopy. Results showed that with the prolongation of reaction time, their morphology changed from linear fibres to carbon micro-bead chains and then again to thicker linear fibres, which led to the increase of the carbon fibres diameters from 200 nm to several micrometers. Furthermore, several kinds of carbon fibres with special morphology such as carbon micro-beads, chains, etc., could be obtained by adjusting the growth time. A growth mechanism, henceforth referred to as fibre-bead-thicker fibre, for the outer layer of vapour grown carbon fibres is proposed.

6

Structure of rolled CuTi4 alloy

100%

Konieczny J. , Rdzawski Z.

Journal of Achievements in Materials and Manufacturing Engineering

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2012

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tom Vol. 50, nr 1

26--39

EN

Purpose: The aim of the work is to investigate the microstructure of the heat treated and cold rolled commercial CuTi4 copper alloy. Design/methodology/approach: Observations an investigations of the structure were made on the JOEL transmission electron microscope (TEM), scanning electron microscope (SEM) Zeiss SUPRA 25 and diffractometer X’Pert Panalytical. Findings: Decomposition of supersaturated solid solution in that alloy is similar to the alloys produced in laboratory scale. The observed differences in microstructure after supersaturation were related to the presence of undissolved Ti particles and increased segregation of titanium distribution in copper matrix including microareas of individual grains. The mentioned factors influence the mechanism and kinetics of precipitation and subsequently the produced wide ranges of functional properties of the alloy. Research limitations/implications: Cold deformation (50% reduction) of the alloy after supersaturation changes the mechanism and kinetics of precipitation and provides possibilities for production of broader sets of functional properties. It is expected that widening of the cold deformation range should result in more complete characteristics of material properties, suitable for the foreseen applications. Similar effects can be expected after application of cold deformation after ageing. Practical implications: The elaborated research results present some utilitarian qualities since they can be used in development of process conditions for industrial scale production of strips from CuTi4 alloy of defined properties and operating qualities. Originality/value: The mentioned factors influence the mechanism and kinetics of precipitation and subsequently the produced wide ranges of functional properties of the Cu-Ti alloys.

7

Structure of monolayer coatings deposited by PVD techniques

100%

Dobrzański L. A. , Lukaszkowicz K. , Labisz K.

Journal of Achievements in Materials and Manufacturing Engineering

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2006

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tom Vol. 18, nr 1-2

271--274

EN

Purpose: The aim of the research is the investigation of the structure of coatings deposited by PVD technique (reactive magnetron sputtering method) onto the substrate from the CuZn40Pb2 brass. Design/methodology/approach: Microstructure was characterised using optical metallography, scanning and transmission electron microscopy. Findings: The hard PVD coatings deposited by reactive magnetron sputtering method demonstrate structure composed of fine crystallites. In case of the monolayer coatings the columnar structure occurs. Examinations of the PVD coating textures reveal that in most cases they have the binary textures {111} and {100} or {110} and {311}. Research limitations/implications: In order to evaluate with more detail the possibility of applying these coatings in tools, further investigations should be concentrated on the determination of the mechanical and tribological properties of the coatings. Originality/value: The paper contributes to better understanding and recognition the structure of thin coatings deposited by PVD techniques.

8

The investigation of experimental combustion engine elements conducted with use of atomic physics methods

100%

Kałużny J. , Iskra A. , Babiak M.

Journal of KONES

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2015

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tom Vol. 22, No. 4

147--154

EN

The authors put forward in earlier publications the concept of using carbon nanotubes (CNT) in order to improve the functional characteristics of selected structural components of internal combustion engines. The main goal of applying carbon nanotubes is to take advantage of its unique properties, which cannot be found among traditional construction materials, to reduce emissions and fuel consumption. To achieve this goal it is essential to come to know about elements and materials behaviour in specific application, for example piston or catalytic converter. In this article, selected methods in the field of atomic physics applied to the study of experimental engine components produced using nanotechnology are presented. For example, the electron microscopy in conjunction with registration of the characteristic X-ray and Raman spectroscopy were used. These test methods are improving the knowledge of the properties and design of pistons and catalytic converters with surface coated with multi-walled carbon nanotubes. The results of elements surface analysis, which were diverted from the engines after a series of test stand investigations, offer insight into the processes that take place in layers of carbon nanotubes in actual engine operating conditions. The knowledge gained with application of atomic physics methods allows achieving further improvement of carbon nanotubes layers and its functional characteristics.

9

Mechanical properties of Co-based amorphous ribbons

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Konieczny J. , Dobrzański L. , Pešek L. , Zubko P.

Journal of Achievements in Materials and Manufacturing Engineering

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2008

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tom Vol. 31, nr 2

254-261

EN

Purpose: The goal of this work was to investigate the influence of chemical composition and isothermal heating in order to determine the change of the mechanical properties of the metallic ribbons by depth sensing indentation technique. Design/methodology/approach: The amorphous metallic ribbons were manufactured by planar-flow-casting method. Instrumented hardness measuring was carried out using the nanohardness tester DUH-202 with a Vickers indenter. Observations of the structure of powders were made on the OPTON DSM-940 scanning electron microscope. The diffraction examinations and examinations of thin foils were made on the JEOL JEM 3010 transmission electron microscope. Findings: The analysis of the mechanical properties and structure of the Co-based amorphous ribbons obtained in the by planar-flow-casting process proved that the no significant differences between both ternary alloys in local mechanical properties HM, EIT and W were observed for amorphous state but differences between ternary and multicomponent alloys were observed. In heat treated state small differences between materials were observed too. Research limitations/implications: For the metallic Co-based amorphous ribbons, further mechanical examinations and structure are planed. Practical implications: Feature an alternative to commercial alloys and composite materials are the amorphous and nanocrystalline metal amorphous ribbons obtained by melt spinning technique and make it possible to obtain the new composite materials with best mechanical properties, whose dimensions and shape can be freely formed. Originality/value: The paper presents influence of annealing temperature and chemical composition of metallic ribbons on martens hardness, indentation modulus EIT, work for deformation and ratio of elastic and total indentation energy. Heating of ribbons obtained by melt spinning technique, to check its effect on changes of mechanical properties. Results and a discussion of the influence of annealing temperature microhardness metallic ribbons is presented.

10

Characterisation of properties and microstructural changes of 12% Cr-W steels after long-term service

100%

Hernas A. , Moskal G. , Rodak K. , Pasternak J.

Journal of Achievements in Materials and Manufacturing Engineering

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2008

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tom Vol. 31, nr 2

312-319

EN

Purpose: Characterization of the influence of long-term exposition on microstructural stability and properties of new modified ferritic steels containing 12% Cr with W addition. Design/methodology/approach: The examinations were made on samples from superheater tubes (HCM12 and HCM12A type of steel) after long term exposition (20 and 30 thousand hours). The major technique used to investigations are: microstructural analysis with the use of LM, SEM and TEM and measurement of hardness and strength at an ambient temperature and at 600° C. Findings: Investigated power plant steels exhibit high stability of microstructeres and mechanical properties. The main effects of degradation are related to the decomposition of martensite areas, the precipitation of M23C6 carbides and Laves' phases, and the processes of recrystallization and recovery. Results of mechanical examinations showed that main mechanical parameters was still satisfactory after 30.000 hours of operation. Research limitations/implications: Presented examination showed that new type of power plant steels are characterized by high stability of the microstructure and properties, however it necessary to identify the mechanisms of structure degradation and, in consequence, of adjusting the mechanical properties below the values required. It is therefore necessary to continue the investigations after successive periods of operation. Practical implications: Presented conclusion give the possibility to the determination of the degree of life-time lost of the investigated high-chromium steels and specification of the time of safety operation. Originality/value: This investigations are valuable contribution to the development of new steels for the power industry. They enable the identification of the degradation mechanisms in steels of new types, which enhances the durability and safety of boilers' operation.

11

The Evolution of Microstructure and Magneto-structural Properties of Heat Treated Ni-Mn-Sn-In Heusler Alloys Sintered by Vacuum Hot Pressing

100%

Maziarz W. , Wójcik A. , Chulist R. , Szczerba M. J. , Kowalczyk M. , Czaja P. , Cesari E. , Dutkiewicz J.

Archives of Metallurgy and Materials

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2019

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tom Vol. 64, iss. 2

727--732

EN

In this work, vacuum hot pressed Ni-Mn-Sn-In Heusler alloys with different concentration of In (0, 2 and 4 at.%), were investigated. The magneto-structural behaviour and microstructure dependencies on chemical composition and on heat treatment were examined. It was found that the martensite start transformation temperature increases with growing In content and to a lesser extent with increasing temperature of heat treatment. The high energy X-ray synchrotron radiation results, demonstrated that both chemical composition as well as temperature of heat treatment slightly modified the crystal structures of the studied alloys. Microstructural investigation performed by transmission electron microscopy confirmed chemical composition and crystal structure changes in the alloys.

12

Structure, texture and chemical composition of coatings deposited by PVD techniques

100%

Dobrzański L. A. , Lukaszkowicz K. , Labisz K.

Archives of Materials Science and Engineering

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2009

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tom Vol. 37, nr 1

45-52

EN

Purpose: The aim of the research is the investigation of the structure, texture and chemical composition of coatings deposited by PVD technique (reactive dc magnetron sputtering method) onto the substrate from the CuZn40Pb2 brass. Design/methodology/approach: Microstructure was characterised using optical metallography, scanning and transmission electron microscopy. Changes of the chemical composition of the coatings were examinations made on the glow discharge optical spectrometer (GDOS). Findings: The hard PVD coatings deposited by reactive dc magnetron sputtering method demonstrate structure composed of fine crystallites. In case of the monolayer coatings the columnar structure occurs. Examinations of the PVD coating textures reveal that in most cases they have the binary textures. Research limitations/implications: In order to evaluate with more detail the possibility of applying these coatings in tools, further investigations should be concentrated on the determination of the mechanical and tribological properties of the coatings. Originality/value: The paper contributes to better understanding and recognition the structure of thin coatings deposited by PVD techniques.

13

Fe-Al based composite reinforced with ultra-fine Al2O3 oxides for high temperature applications

100%

Kopec M. , Jóźwiak S. , Kowalewski Z.

Journal of Theoretical and Applied Mechanics

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2021

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tom Vol. 59 nr 3

509--513

EN

In this paper, an Fe-Al based composite reinforced with ultra-fine Al2O3 oxides was obtained through sintering of aluminium, iron and mullite ceramic powders using self-propagated high temperature synthesis (SHS). The powder mixture with a 50%wt. content of the ceramic reinforcement was cold pressed and subsequently subjected to the sintering process in vacuum at 1200◦C for 25 minutes under external loading of 25 kN. The complex microstructure of the Fe-Al matrix reinforced with ultra-fine Al2O3 oxides was found to be desired in high temperature applications since only 3% of the relative weight gain was observed after 100 hours of annealing at 900◦C.

14

Fabrication of yttria stabilized zirconia nanoparticles by the reverse microemulsionmethod for SOFC applications

100%

Vatansever S. , Öksüzömer F. , Naci Koç S. , Somer M. , Deligöz H. , Gürkaynak M. A.

Materials Science Poland

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2010

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tom Vol. 28, No. 1

85--91

EN

Yttria stabilized zirconia powders were synthesized by the reverse microemulsion method. Powders were calcined from 600 °C to 1000 °C and sintered at 1450 °C. Crystalline properties and microstructure of samples were characterized by X-ray diffraction and scanning electron microscopy, respectively. Oxygen ionic conductivity was measured by electrochemical impedance spectroscopy. Sizes of yttria stabilized zirconia particles calcined at 1000 °C are lower than 100 nm, and approximately, 1 žm grain was obtained after sintering at 1450 °C.

15

Advanced microstructure diagnostics and interface analysis of modern materials by high-resolution analytical transmission electron microscopy

100%

Neumann W. , Kirmse H. , Hausler I. , Mogilatenko A. , Zheng C. , Hetaba W.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2010

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tom Vol. 58, nr 2

237-253

EN

Transmission electron microscopy (TEM) is a powerful diagnostic tool for the determination of structure/property relationships of materials. A comprehensive analysis of materials requires a combined use of a variety of complementary electron microscopical techniques of imaging, diffraction and spectroscopy at an atomic level of magnitude. The possibilities and limitations of quantitative TEM analysis will be demonstrated for interface studies of the following materials and materials systems: Nickel-based superalloy CMSX-10, (Zn,Cd)O/ZnO/Al2O3, (Al,Ga)N/AlN/Al2O3, GaN/LiAlO2 and FeCo-based nanocrystalline alloys.

16

Synthesis and formation process of zirconium dioxide nanorods

100%

Pei L. Z. , Xie Y. K. , Pei Y. Q. , Yuan C. Z.

Materials Science Poland

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2013

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tom Vol. 31, No. 2

186--192

EN

Crystalline zirconium dioxide nanorods have been prepared by a simple hydrothermal process using zirconium hydroxide as the zirconium raw material. Zirconium dioxide nanorods are composed of monoclinic zirconium dioxide phase, which has been confirmed by the X-ray diffraction analysis. Electron microscopy observations show that the zirconium dioxide nanorods have a single crystal structure, with the rod diameter of less than 100 nm and length of 1 – 2 m. Hydrothermal temperature and reaction time play essential roles in the formation and growth of the zirconium dioxide nanorods. Nucleation and crystal growth process are proposed to explain the formation and growth of the zirconium dioxide nanorods.

17

Effect of structure parameters and composition of high-silica porous glasses on their thermal and radiation resistant properties

100%

Antropova T. V. , Volkova A. V. , Petrov D. V. , Stolyar S. V. , Ermakova L. E. , Sidorova M. P. , Yakovlev E. B. , Drozdova I. A.

Optica Applicata

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2005

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tom Vol. 35, nr 4

717-723

EN

The influence of a composition of initial phase-separated alkali borosilicate glass and its thermal treatment as well leaching conditions on the parameters of the porous glass structure are discussed. The results obtained by adsorption and conductivity methods, transmission electron microscopy and dilatometer technique were used to analyse the effect of structure parameters and composition of high-silica porous glasses on their thermal and radiation resistant properties.

18

Morphology and distribution of phage-like particles in a eutrophic boreal lagoon

100%

Sulcius S. , Staniulis J. , Paškauskas R.

Oceanologia

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2011

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tom No. 53 (2)

587-603

EN

In this paper we present the results of direct observations of the morphology and size of phage-like particles by means of transmission electron microscopy (TEM) as a function of their spatial distribution in the shallow highly productive Curonian Lagoon of the Baltic Sea. In total, 26 morphologically different forms of phage-like particles were found. Different trends of distribution in terms of abundance, size and shape of virus-like particles were demonstrated. The total abundance of viruses varied from 1.91×107 ml-1 to 5.06×107,/sup. ml-1. The virus to bacteria ratio (VBR) changed from 15.6 to 49 and was negatively associated with total bacterial numbers (r = -0.60; p < 0.05). The phages of family Myoviridae were the most diverse and were dominant at all stations.

19

Microstructure of Multi-Component Ni35Ti35Ta10Co10Cu10 Alloy

100%

Glowka K. , Zubko M. , Świec P. , Prusik K. , Dercz G. , Matyja E. , Stróż D.

Archives of Metallurgy and Materials

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2019

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tom Vol. 64, iss. 2

715--719

EN

A new NiTi-based multi-component Ni35 Ti35 Ta10 Co10 Cu10 (at.%) alloy was obtained by vacuum arc melting. The microstructure of the alloy has been studied using scanning and transmission electron microscopy, backscatter electron diffraction and X-ray diffraction techniques. The performed measurements showed presence of two cubic and one tetragonal phases. Energy dispersive X-ray spectroscopy analysis confirmed that all the observed phases contained all five principal elements.

20

Synthesizing cysteine-coated magnetite nanoparticles as MRI contrast agent: Effect of pH and cysteine addition on particles size distribution

100%

Ahmadi R. , Ranjbarnodeh E. , Gu N.

Materials Science Poland

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2012

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tom Vol. 30, No. 4

382--389

EN

Cysteine capped magnetite nanoparticles (10 to 20 nm) were synthesized via coprecipitation method under ultrasonic irradiation. The influence of pH value of the solution and cysteine addition on the size distribution and hydrodynamic size of nanoparticles were studied via TEM and PCS methods, respectively. The crystal structure and magnetic properties of the nanoparticles were characterized by XRD and VSM techniques, respectively. Coating density was calculated using TGA and TEM results. Cytotoxicity assessment performed by incubation of L929 cells, confirmed that ferrofiuids are biocompatible. MRI studies conducted on rats demonstrated suitability of synthesized nanoparticles as contrast agents, especially for imaging of the lymph nodes.