Effects of Sm3+ on Microstructure and Magnetic Properties of Ni0.4Zn0.6SmxFe2-XO4(x=0~0.07) Ferrites

2014 ◽  
Vol 1053 ◽  
pp. 97-102
Author(s):  
Yong Wang Yan ◽  
Xiu Feng Fan
Keyword(s):  
Magnetic Properties ◽  
Spinel Phase ◽  
Magnetic Loss ◽  
Solid State Reaction Method ◽  
Lattice Parameter ◽  
Minor Effect ◽  
Conventional Solid State Reaction ◽  
A Minor ◽  
Microstructure And Magnetic Properties ◽  
Super Exchange Interaction

The effects of Fe3+substitutions by Sm3+on microstructure and magnetic properties of Ni0.4Zn0.6Fe2-xSmxO4ferrites prepared by conventional solid-state reaction method were investigated. With increasing Sm3+content, the lattice parameter ɑ and sintered density of sintered samples increase, while the real part of permeability and magnetic loss tangent decrease. Samples carried out at 1250°C for 4h resulted in materials with cubic spinel phase, but a small amount of SmFeO3was also formed. Magnetic properties results showed that the super-exchange interaction between octahedral B sites and tetrahedral A sites was badly impaired and the net overall magnetic moment (m=mB-mA) has an obvious decrease. It was also found that in these compounds Fe-Fe interaction dominates, the Sm-Fe interaction (3d-4f coupling) having a minor effect.

Effect of Cu-Excess on the Microstructure and Microwave Dielectric Properties of CaCu3Ti4O12 Ceramics

2015 ◽  
Vol 1087 ◽  
pp. 50-54 ◽  
Author(s):  
Mohamad Johari Abu ◽  
Julie Juliewatty Mohamed ◽  
Mohd Fadzil Ain ◽  
Zainal Arifin Ahmad
Keyword(s):  
Dielectric Constant ◽  
Microwave Dielectric Properties ◽  
Secondary Phase ◽  
Solid State Reaction Method ◽  
Lattice Parameter ◽  
Tangent Loss ◽  
Conventional Solid State Reaction ◽  
Microwave Dielectric ◽  
Order Of Magnitude ◽  
Grain Growth Behavior

CaCu(3+x)Ti4O12 (CCTO) ceramics with different Cu-excess (x = 0 – 0.6) were prepared by conventional solid-state reaction method. Characterization of the prepared ceramics with XRD and FESEM showed that lattice parameter and grain size are slightly increased, indicating Cu-excess to have the big impact on the both phase structure and microstructure. The XRD profiles indicated that the secondary phase (CuO or Cu2O) existed at edge/corner of CCTO grain, which promoted inhibited grain growth behavior. The CCTO ceramics exhibited two trends of dielectric constant related to frequency, which showed a flatter curve about ~50 in 1 – 25 GHz regions, and it’s dropped rapidly to ~35 in 25 – 50 GHz region. With Cu-excess, the dielectric constant of the ceramics was increased for an average of a quarter-order of magnitude, while the tangent loss also increased up to triple times than x = 0, for the same frequency range. Despite enormous increase of dielectric constant related to varying Cu-excess, the tangent loss also increased.

Determination of Optimum Annealing Time Durations of Nano Boron Nitride Added MgB2 Superconductors

2018 ◽  
Vol 2 (2) ◽  
Author(s):  
Asaf Tolga Ulgen
Keyword(s):  
Boron Nitride ◽  
Annealing Time ◽  
Hexagonal Boron Nitride ◽  
Superconducting Magnet ◽  
Solid State Reaction Method ◽  
Lattice Parameter ◽  
Residual Resistivity ◽  
Conventional Solid State Reaction ◽  
Cross Sectional ◽  
Sintering Time

In the present study, I have investigated the effect of different annealing time durations of 0.5h, 1h, 2h and 4h (annealing temperature at 700oC) on the electrical, micro structural and superconducting properties of the nano hexagonal boron nitride (hBN) added/doping magnesium diboride (MgB2) superconducting samples. The aim of this work, hBN added MgB2 superconducting bulk samples are determined to find out the optimum sintering time, also investigated how BN addition effects the optimum fabrication conditions. These superconducting samples were prepared by the conventional solid-state reaction method. Experimental techniques of X-ray diffraction (XRD) were used for structural and microstructural examinations. Critical transition temperatures, difference between Tc-onset and Tc-offset, a and c lattice parameter, grain size, bulk density, residual resistivity ratios (RR) and cross-sectional area fractions (AF) of the pure and nano-hBN added MgB2 materials are obtained using a cryostat equipped with a superconducting magnet. All the experimental results notice that the characteristic features improve regularly with the increment in sintering time durations. 

EFFECT OF COPPER OXIDE ON THE GRAIN GROWTH AND INITIAL PERMEABILITY OF Mg–Cu–Zn FERRITES

2010 ◽  
Vol 24 (02) ◽  
pp. 169-182
Author(s):  
M. MANJURUL HAQUE ◽  
M. HUQ ◽  
SYED FARID UDDIN FARHAD ◽  
JASIM UDDIN KHAN ◽  
M. A. HAKIM
Keyword(s):  
Grain Size ◽  
Magnetic Properties ◽  
Grain Growth ◽  
Spinel Phase ◽  
Initial Permeability ◽  
Cu Content ◽  
Average Grain Size ◽  
Zn Ferrite ◽  
Effect Of Copper ◽  
Microstructure And Magnetic Properties

The microstructure and magnetic properties of Mg – Cu – Zn ferrites prepared by using solid-state reaction method have been investigated. X-ray diffraction (XRD), a scanning electron microscope (SEM), impedance analyzer and a vibrating sample magnetometer (VSM) were utilized in order to study the effect of copper substitution and its impact on the crystal structure, grain size, microstructure and magnetic properties of the Mg – Cu – Zn ferrite. The formation of cubic spinel phase was identified using XRD technique. The microstructures of the samples show that the grain growth is greatly enhanced by the addition of CuO which is attributed to the liquid phase during sintering. The average grain size (Dm) increases significantly with increasing Cu content. The initial permeability (μ') of the samples increases appreciably with increasing Cu content which is attributed to the increase of grain size and density of the samples. The resonance frequency (fr) of the samples shifts toward the lower frequency as the Cu content increases. The sharp fall of μ' in μ'-T curves is observed for all the samples which indicate the homogeneity of the samples. The saturation magnetization (Ms) of the Mg – Cu – Zn ferrites increases slightly with increasing Cu concentration.

Structural and Dielectric Analysis of La0.88Bi0.12Mn0.80Ni0.20O3 Composite

2021 ◽  
Vol 317 ◽  
pp. 35-45
Author(s):  
Aaliyawani Ezzerin Sinin ◽  
Walter Charles Primus ◽  
Zainal Abidin Talib ◽  
Chen Soo Kien ◽  
Abdul Halim Shaari ◽  
...  
Keyword(s):  
Dielectric Loss ◽  
Sintering Temperature ◽  
Solid State Reaction Method ◽  
Lattice Parameter ◽  
Rhombohedral Structure ◽  
X Ray Diffraction ◽  
Conventional Solid State Reaction ◽  
X Ray ◽  
A Value ◽  
Electric Behavior

Composite La0.88Bi0.12Mn0.80Ni0.20O3 was synthesized using the conventional solid-state reaction method with sintering temperature of 1200 °C for 12 hours and the dielectric properties investigated. The X-ray diffraction result shows that the composite has a rhombohedral structure with lattice parameter of a = b = c = 5.5136 Ǻ. Scanning electron microscope shows grains with approximately from 0.8 to 5.4 μm in size with presence of voids. The dielectric permittivity, εʹ and dielectric loss, εʺ were measured in the range of 298 K to 473 K where both are temperature and frequency dependent. At 1 kHz to 100 kHz, the εʹ is around 10000 and the dielectric loss tangent, tan δ is below 1.5. The electric behavior of this composite is best represented by Quasi-dc model which consists of two universal capacitors in parallel. Parameters value from the fitting indicated that high correlations of electrons between inter and intra-clusters. The activation energy, Ea calculated from the conductivity of the sample gives a value of 0.116 eV. Vibrating sample magnetometer shows that the La0.88Bi0.12Mn0.80Ni0.20O3 has a magnetic coercivity, Hc of 36.109 G and retentivity, Br, valued 2.7504 x 10-3 emu/g.

Effect of Cd2+ Substitution on the Magnetic Properties of NiCuZn Ferrites for Low Temperature Firing

2014 ◽  
Vol 602-603 ◽  
pp. 931-935
Author(s):  
Hui Zhang ◽  
Xi Yun He ◽  
Xia Zeng ◽  
Ying Shi
Keyword(s):  
Magnetic Properties ◽  
Solid State ◽  
Loss Factor ◽  
Solid State Reaction Method ◽  
Lattice Parameter ◽  
Anisotropy Constant ◽  
Initial Permeability ◽  
Reaction Method ◽  
Magnetic Anisotropy Constant ◽  
The Difference

Cd2+-substituted NiCuZn ferrites with compositions of Ni0.24-yCdyCu0.21Zn0.55Fe1.92O3.88(y = 0.00, 0.002, 0.005, 0.007, 0.01) were prepared by a solid state reaction method. The effects of Cd2+substitution on phase, microstructure feature and magnetic properties of samples were discussed. The results showed that NiCuZn ferrites with Cd2+substitution were single spinel phases. The lattice parameter decreased first and subsequently increased due to the difference of ions radius and incomplete substitution. The density of sintered samples had similar trend as well. The saturation magnetizationMSdecreased with the increase of Cd2+ions. The highest initial permeabilityμiand lowest relative loss factortanδ/μiwere found in the composition with Cd contenty=0.007 attributed to the decrease of crystal magnetic anisotropy constantK1of the ferrites.

scholarly journals Microstructure And Magnetic Properties Of The FeZr(Y)NbCuB Amorphous Alloys

2015 ◽  
Vol 60 (2) ◽  
pp. 1071-1074 ◽  
Author(s):  
J. Gondro ◽  
K. Błoch ◽  
M. Nabiałek ◽  
K. Waltters ◽  
M. Szota
Keyword(s):  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Chemical Composition ◽  
Curie Temperature ◽  
Amorphous Alloys ◽  
X Ray ◽  
Low Field ◽  
A Minor ◽  
Structure And Microstructure ◽  
Microstructure And Magnetic Properties

Abstract In this paper, the results of investigations are presented, into the microstructure and magnetic properties of the following amorphous alloys in the as-quenched state: Fe82Zr7Nb2Cu1B8 and Fe86Zr4Y3Nb1Cu1B5. The studied material was produced in the form of thin ribbons of 3 mm width and 20 μm thickness. The structure and microstructure of the samples have been investigated by means of Mössbauer spectrometry and X-ray diffractometry. In addition, the magnetic properties of these materials have been determined, i.e. the low-field magnetic susceptibility, and the magnetisation as a function of temperature and magnetising field. On the basis of the performed investigations, it has been found that a minor change in the quantities of elements favouring amorphisation, such as: Zr and Y, has an influence on the value of the Curie temperature and the magnetic properties of the resulting alloys. It should be noticed that the changes, introduced in the chemical composition of the alloys, don’t change the combined volume of these elements, i.e. Zr7 and Zr4Y3.

scholarly journals Superconductivity in LiGa2Ir Heusler type compound with VEC = 16

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Karolina Górnicka ◽  
Gabriel Kuderowicz ◽  
Michał J. Winiarski ◽  
Bartłomiej Wiendlocha ◽  
Tomasz Klimczuk
Keyword(s):  
Heat Capacity ◽  
Solid State Reaction Method ◽  
Lattice Parameter ◽  
Coupling Constant ◽  
X Ray Diffraction ◽  
Electron Phonon Interaction ◽  
Type Ii Superconductor ◽  
Electron Phonon Coupling ◽  
A Minor ◽  
Type Crystal

AbstractPolycrystalline LiGa2Ir has been prepared by a solid state reaction method. A Rietveld refinement of powder x-ray diffraction data confirms a previously reported Heusler-type crystal structure (space group Fm-3m, No. 225) with lattice parameter a = 6.0322(1) Å. The normal and superconducting state properties were studied by magnetic susceptibility, heat capacity, and electrical resistivity techniques. A bulk superconductivity with Tc = 2.94 K was confirmed by detailed heat capacity studies. The measurements indicate that LiGa2Ir is a weak-coupling type-II superconductor ($${\uplambda }$$ λ e–p = 0.57, $${\Delta }$$ Δ C/$${\upgamma }$$ γ Tc = 1.4). Electronic structure, lattice dynamics, and the electron–phonon interaction are studied from first principles calculations. Ir and two Ga atoms equally contribute to the Fermi surface with a minor contribution from Li. The phonon spectrum contains separated high frequency Li modes, which are seen clearly as an Einstein-like contribution in the specific heat. The calculated electron–phonon coupling constant $${\uplambda }$$ λ e–p = 0.68 confirms the electron–phonon mechanism for the superconductivity. LiGa2Ir and recently reported isoelectronic LiGa2Rh are the only two known representatives of the Heusler superconductors with the valence electron count VEC = 16.

scholarly journals Superconducting Properties of Bi2-xPb0.3WxSr2Ca2Cu3O10+ Compounds

2021 ◽  
pp. 490-495
Author(s):  
Mohammed J. Tuama ◽  
Lamia K. Abbas
Keyword(s):  
Volume Fraction ◽  
Solid State Reaction Method ◽  
Lattice Parameter ◽  
Crystallographic Structure ◽  
Nominal Composition ◽  
X Ray Diffraction ◽  
Conventional Solid State Reaction ◽  
X Ray ◽  
Two Phases ◽  
Parameter Values

The conventional solid-state reaction method was utilized to prepare a series of superconducting samples of the nominal composition Bi2-xPb0.3WxSr2Ca2Cu3O10+d with 0≤x≤0.5 of 50 nm particle size of tungsten sintered at 8500C for 140h in air . The influence of substitution with W NPs at bismuth (Bi) sites was characterized by the X-ray diffraction (XRD), scanning electron microscopy (SEM) and dc electrical resistivity. Room temperature X-ray diffraction analysis revealed that there exists two phases, i.e. Bi-(2223) and Bi-(2212), in addition to the impurity phases of (SrCa) 2Cu2O3, Sr2Ca2Cu7Oδ, Ca2PbO4, CaO, and WO. It was found that the crystallographic structure of all samples was orthorhombic. Lattice parameter values and the volume fraction of the (2223)-phase of the prepared samples were also calculated. The superconductivity transition temperature (Tc) for samples subjected to substitution with W NPs was found to be higher than that for the pure sample. The optimal value of W NPs content in (Bi, Pb)-2223 system was found to be at x=0.3. 

scholarly journals Effect of Y3+ Substitution on Structural and Magnetic Properties of Ni0.25 Zn0.75YxFe2-xO4

2020 ◽  
Vol 68 (2) ◽  
pp. 111-116
Author(s):  
Sharmin Akhter ◽  
Probal Roy ◽  
Armin Anwar ◽  
MA Hossain ◽  
MNI Khan ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Solid State Reaction Method ◽  
Industrial Applications ◽  
Ferromagnetic Behavior ◽  
Conventional Solid State Reaction ◽  
Spinel Type ◽  
Sem Micrographs ◽  
Ray Density ◽  
Structural And Magnetic Properties ◽  
Xrd Patterns

The effect of Y3+ doping on the structural and magnetic properties of Ni0.25 Zn0.75YxFe2-xO4 [x= 0.00, 0.02, 0.04, 0.06 and 0.08] was investigated. The specimen was synthesized by conventional solid state reaction method where the sintering temperature was 1150oC for 3 hours. The structure of the specimens was inspected by XRD pattern and SEM micrographs. The XRD patterns delineate the formation of spinel type cubic structure. The lattice parameters, bulk density, X-ray density and porosity were investigated for all the samples. The SEM micrographs shows that the particles of all the composition are within 0.4 – 1.2 μm. M-H curves at room temperature exhibit the ferromagnetic behavior. The effect of Y3+ causes drastically variation on saturation magnetization (Ms), coercivity (Hc) and remanent magnetization (Mr). Moreover, the M-H curves delineate the soft ferromagnetic phenomenon which can be the reason of the acceptance of the specimen in industrial applications. Dhaka Univ. J. Sci. 68(2): 111-116, 2020 (July)

scholarly journals A comparison study of the Structural and magnetic properties of pure Ni metal and NiZnMn ferrite

2019 ◽  
Vol 17 (43) ◽  
pp. 18-25
Author(s):  
Muthafer F. Al-Hilli
Keyword(s):  
Magnetic Properties ◽  
Spinel Phase ◽  
Magnetic Loss ◽  
Cubic Phase ◽  
Comparison Study ◽  
X Ray Diffraction ◽  
Nickel Metal ◽  
X Ray ◽  
Nickel Zinc ◽  
Laboratory Setup

The magnetic properties of a pure Nickel metal and Nickel-Zinc-Manganese ferrites having the chemical formula Ni0.1(Zn0.4Mn0.6)0.9Fe2O4 were studied. The phase formation and crystal structure was studied by using x-ray diffraction which confirmed the formation of pure single spinel cubic phase with space group (Fd3m) in the ferrite. The samples microstructure was studied with scanning electron microstructure and EDX. The magnetic properties of the ferrite and nickel metal were characterized by using a laboratory setup with a magnetic field in the range from 0-500 G. The ferrite showed perfect soft spinel phase behavior while the nickel sample showed higher magnetic loss and coercivity.

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