scholarly journals MAGNETIC AND MICROWAVE ABSORPTION PROPERTIES OF NEODYMIUM DOPED NICKEL FERRITE USING MILLING TECHNIQUE

2019 ◽  
Vol 81 (4) ◽  
Author(s):  
Yunasfi Yunasfi ◽  
Mashadi Mashadi ◽  
Ade Mulyawan
Keyword(s):  
Nickel Ferrite ◽  
Magnetic Measurement ◽  
Spinel Ferrite ◽  
Solid State Reaction Method ◽  
High Energy ◽  
Morphological Observation ◽  
Ferromagnetic Behavior ◽  
X Ray Diffraction ◽  
Diffraction Patterns ◽  
Compound Materials

Nickel ferrite doped by neodymium in the form of (Ni(1-x)NdxFe2O4) with (x =  0.0 ; 0.2 and 0.4) have been synthesized using solid state reaction method with milling technique from NiO, Nd2O3 and Fe2O3 powder. The mixture of those compound materials was milled using High Energy Milling (HEM) machine for 10 hours and then sintered at 1000 °C for 5 h. X-ray diffraction patterns showed that a single phase of spinel ferrite has been formed in all of the compositions. The result of morphological observation using Scanning Electron Microscope (SEM) exhibited a homogeneous structure has been formed with particle size about 200 nm. The magnetic measurement using vibrating sample magnetometer (VSM) showed that the sample exhibited a ferromagnetic behavior, where the Ms value decrease (around of 58.4 to 39.40 emu/g) and value of Hc increased (around of 116-170 Oe) along with the addition of the Nd3+ ion (x values) content. While the ability of microwaves absorption measured by using Vector Network Analyzer (VNA) indicates that the maximum value of Reflection Loss (RL) obtained at the composition of x = 0.4 up to -29 dB at a frequency of 10.81 GHz. It means the Ni0,6Nd0,4Fe2O4 sample can absorb microwave up to ~ 96.5% at a frequency of 10.81 GHz.

scholarly journals Magnetic and microwave absorption properties of nickel ferrite (NixFe3-xO4) by HEM technique

2017 ◽  
Vol 13 (3) ◽  
Author(s):  
Yunasfi Yunas ◽  
Wisnu Ari Adi ◽  
Mashadi Mashadi ◽  
Putri Astari Rahmy
Keyword(s):  
Nickel Ferrite ◽  
Single Phase ◽  
Magnetic Measurement ◽  
High Energy ◽  
Infrared Analysis ◽  
X Ray Diffraction ◽  
Absorption Bands ◽  
Absorption Properties ◽  
Microwave Absorption Properties ◽  
Maximum Value

Nickel ferrite (NixFe3-xO4) have been synthesized using solid state reaction with composition (2x)NiO : (3-x)Fe2O3 (x = 0.5; 1.0; 1.5 dan 2.0) in mol in wt%. Mixing of this powder was milled with HEM (High Energy Milling) for 10 hours, and then sintered at 1000 °C for 3 h. X-ray diffraction pattern indicates that the all of samples are single phase in this stage. FTIR (Fourier transform infrared) analysis showed two absorption bands in the range of ~410 - ~600 cm-1 related to octahedral and tetrahedral sites. The magnetic measurement using vibrating sample magnetometer (VSM) shows that the sample exhibited a ferromagnetic behaviour with its coercivity value in the range of 164-217 Oe, and the maximum value wasshowed by x =1.5. VNA (Vector Network Analyzer) characterization shows the ability electromagnetic wave absorption with RL (reflection loss) value of -28 dB occurs at frequency of 10.98 GHz. It means that the Ni1.5Fe1.5O4 sample can absorb microwave about ~96 % at 10.98 GHz.

Structural and electrochemical properties of Ti–Ru–Fe–O alloys prepared by high energy ball-milling

1998 ◽  
Vol 13 (5) ◽  
pp. 1171-1176 ◽  
Author(s):  
S-H. Yip ◽  
D. Guay ◽  
S. Jin ◽  
E. Ghali ◽  
A. Van Neste ◽  
...  
Keyword(s):  
Electrochemical Properties ◽  
High Energy ◽  
X Ray Diffraction ◽  
Long Term Stability ◽  
Ternary Metal ◽  
Oxide Phases ◽  
Energy Ball ◽  
Diffraction Patterns ◽  
B2 Structure

The structural and electrochemical properties of the Ti–Ru–Fe–O system have been studied over the whole ternary metal compositional range, keeping constant the oxygen content at 30 at.%. The phase diagram was explored systematically by varying the composition of the material along one of the following axes: (i) constant Ru content of 16 at. %; (ii) constant Ti/Ru ratio of 2; (iii) constant Ti/Fe ratio of 1.6. For O/Ti ratios equal or below unity, the most prominent peaks observed in the x-ray diffraction patterns belong to a B2 structure. For O/Ti ratio larger than unity, stable titanium oxide phases are formed, which coexist with a cubic Fe-like or hcp-Ru like phases depending on the Fe/Ru ratio. Powder compositions with stoichiometry close to Ti2RuFeO2 are of interest due to good electrocatalytic properties, long-term stability, and low Ru content.

Obtaining of the Ir-Al Nanocrystalline Powders by Mechanical Alloying

2011 ◽  
Vol 672 ◽  
pp. 171-174
Author(s):  
Ionel Chicinaş ◽  
P. Cârlan ◽  
Florin Popa ◽  
Virgiliu Călin Prică ◽  
Lidia Adriana Sorcoi
Keyword(s):  
Mechanical Alloying ◽  
Particle Morphology ◽  
High Energy ◽  
Atomic Ratio ◽  
Planetary Mill ◽  
Nanocrystalline Powders ◽  
Alloy Formation ◽  
X Ray Diffraction ◽  
Chemical Homogeneity ◽  
Diffraction Patterns

The Ir-Al powder in the 1:1 atomic ratio was obtained by high energy mechanical alloying in a Pulverisette 4 Fritch planetary mill. The final product was obtained after 28 h of milling in argon atmosphere. Alloy formation was investigated by X-ray diffraction. After 4 h of milling the new structure of IrAl compound is found in the diffraction patterns. The obtained powders are nanocrystalline with a mean crystallite size of 11 nm after 28 h of milling. The particle morphology and the chemical homogeneity were studied using scanning electron microscopy (SEM) and energy dispersive spectrometry (EDX). It was found that the obtained compound present large particles composed by smaller one.

Molecular Beam Epitaxial Growth of Nonpolar a-plane InN/ GaN Heterostructures

2012 ◽  
Vol 1396 ◽  
Author(s):  
Mohana K. Rajpalke ◽  
Thirumaleshwara N. Bhat ◽  
Basanta Roul ◽  
Mahesh Kumar ◽  
S. B. Krupanidhi
Keyword(s):  
Schottky Barrier ◽  
Molecular Beam ◽  
Schottky Barrier Height ◽  
High Energy ◽  
Scanning Electron Micrographs ◽  
X Ray Diffraction ◽  
X Ray ◽  
Molecular Beam Epitaxial ◽  
Diffraction Patterns ◽  
Molecular Beam Epitaxial Growth

ABSTRACTNonpolar a-plane InN/GaN heterostructures were grown by plasma assisted molecular beam epitaxy. The growth of nonpolar a- plane InN / GaN heterostructures were confirmed by high resolution x-ray diffraction study. Reflection high energy electron diffraction patterns show the reasonably smooth surface of a-plane GaN and island-like growth for nonpolar a-plane InN film, which is further confirmed by scanning electron micrographs. An absorption edge in the optical spectra has the energy of 0.74 eV, showing blueshifts from the fundamental band gap of 0.7 eV. The rectifying behavior of the I-V curve indicates the existence of Schottky barrier at the InN and GaN interface. The Schottky barrier height (φb) and the ideality factor (η) for the InN/GaN heterostructures found to be 0.58 eV and 2.05 respectively.

Molecular Beam Epitaxy Growth and Structural Characterization of Si/GaAs Superlattices

1992 ◽  
Vol 263 ◽  
Author(s):  
R.J. Matyi ◽  
H.J. Gillespie ◽  
G.E. Crook ◽  
J.K. Wade
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
High Energy ◽  
Structural Quality ◽  
Molecular Beam Epitaxy Growth ◽  
X Ray Diffraction ◽  
Superlattice Structure ◽  
Dynamical Simulation ◽  
Diffraction Patterns ◽  
High Level

ABSTRACTThe growth of high quality Si/GaAs superlattices on GaAs substrates using molecular beam epitaxy is described. A typical superlattice structure consisted of ten periods of thin (<5Å) layers of pseudomorphic silicon alternating with thick GaAs layers; typical GaAs thicknesses range from 100Å to 1850Å. In situ reflection high energy electron diffraction analysis of the structures during growth showed the silicon layers developed a (3 ×1) reconstruction, while the GaAs exhibited a (4×2)→(3×2)→(3×1)→(2×4) reconstruction sequence. Both observations agree with prior studies of the growth of embedded silicon in GaAs/Si/GaAs heterostructures. X-ray diffraction using the (004) reflection showed sharp and intense satellite peaks (out to 22 orders in one case), indicating a high level of structural quality. Very good agreement has been obtained between observed diffraction patterns and those calculated via dynamical simulation.

Effects of Mechanical Alloying on the Structure and Properties of Iron Powders

2015 ◽  
Vol 364 ◽  
pp. 132-138
Author(s):  
F. Lemdani ◽  
Mohammed Azzaz ◽  
K. Taïbi ◽  
A. Lounis
Keyword(s):  
Magnetic Behavior ◽  
High Energy ◽  
The Body ◽  
X Ray Diffraction ◽  
Laser Scattering ◽  
Different Types ◽  
Bcc Structure ◽  
Electron Microscopes ◽  
Diffraction Patterns ◽  
Scanning Electron Microscopes

A nanostructured iron, elaborated from pure elemental powders by mechanical milling at high energy was characterized by different types of technical of analysis. Scanning electron microscopes (SEM) and laser scattering machine have showed the variation in the size and the shape of particles according to different milling times. Powders obtained were characterized with X-ray diffraction (XRD) , the latter diffraction patterns indicated the body centered cubic (bcc) structure. The crystalline grain was about 13 nm size after only a few hours of milling time. The measurement of both coercive field (Hc) and maximal magnetization (Ms) revealed a change in the magnetic behavior of our samples.

Epitaxial Deposition of 3C-SiC on Si Using Unconventional Sputtering of a Hollow Cathode

2010 ◽  
Vol 1246 ◽  
Author(s):  
James L Huguenin-Love ◽  
Rodney J Soukup ◽  
Natale J Ianno ◽  
Nole T Lauer
Keyword(s):  
Electron Diffraction ◽  
Hollow Cathode ◽  
High Energy ◽  
Bragg Diffraction ◽  
X Ray Diffraction ◽  
Pulsed Dc ◽  
Transmission Electron ◽  
Pole Figures ◽  
Epitaxial Deposition ◽  
Diffraction Patterns

AbstractEpitaxial 3C-SiC was grown using an unconventional technique for epitaxial growth. Thin films of 3C-SiC were deposited onto the (111) and (110) faces of Si using pulsed DC sputtering of a high purity, hollow cathode SiC target. The films were studied using x-ray diffraction (XRD), reflection high energy electron diffraction (RHEED), transmission electron microscopy (TEM), and auger electron spectroscopy (AES) techniques. XRD results presented as Bragg diffraction spectra and pole figures, and electron diffraction patterns verify crystal orientation and epitaxy. In addition, AES profiles identify the compositional integrity of the deposited films.

Structural and Luminescence Properties of Eu3+ and Dy3+ Doped Magnesium Tellurite Borophosphate Ceramic

2015 ◽  
Vol 1107 ◽  
pp. 53-58
Author(s):  
Siti Maisarah Aziz ◽  
Rosli Hussin ◽  
N.M. Yusoff
Keyword(s):  
Solid State ◽  
Emission Spectra ◽  
Solid State Reaction Method ◽  
Luminescence Properties ◽  
Functional Material ◽  
X Ray Diffraction ◽  
Co Doping ◽  
Powder Samples ◽  
Diffraction Patterns ◽  
Co Doped

Lately, researchers have been considering the miscellaneous in the borophosphate crystalline’s luminescence as one of the important properties in hunt of the new functional material. In this study we discus the structural and luminescence properties of Eu3+/Dy3+ co-doped borophosphate ceramic. A series of ceramic samples based on B2O3-(65-)P2O5-25MgO-10TeO2 where (065) mol has successfully been prepared using solid state reaction method and sintered at 900°C. The crystalline phase of the powder samples was characterized using X-ray diffraction pattern. The diffraction patterns analysis indicated that the prepared samples were polycrystalline phase of B(PO4), Mg(PO3)2and Mg(BO3)(PO4). The local structure network structure has been investigated using Infrared Spectroscopy using KBr method. The FT-Infrared spectra reveal the presence of B-O-B vibrations, BO3 and BO4 bridging oxygen and P-O stretching modes of P-O-P, P=O and PO4 unit in the ceramics sample. Meanwhile, the luminescence properties of doped sample were measured based on analysis of emission spectra of photoluminescence spectroscopy. The emission peaks of Eu3+ doped sample were located at 593 nm, 613 nm, 652 nm, 685 nm due to the assigned transition 5D0-7FJ( J = 1, 2, 3, 4 ). The Dy3+ emission is due to 4F9/2 -5H15/2 and 4F9/2-6H13/2 transition. For Eu3+/Dy3+ co-doped sample consists of peaks belonging to the 4F9/2-6H15/2 (482 nm) and 4F9/2-6H13/2 (573 nm) transition while red emission 5D0-7F2 transitions appears at 611 nm. Improvement in the optical properties due to co-doping may be useful to discover a new highly efficient luminescent material that are very useful in optical devices and solid-state lighting.

EFFECT OF Ni ON THE ELECTRICAL AND MICROSTRUCTURAL PROPERTIES OF NANOCRYSTALLITES Fe2O3/TiO2 SYSTEM

2006 ◽  
Vol 13 (04) ◽  
pp. 479-484 ◽  
Author(s):  
MAGED S. SOBHY
Keyword(s):  
Electrical Resistivity ◽  
Spinel Ferrite ◽  
Average Crystalline Size ◽  
X Ray Diffraction ◽  
X Ray ◽  
Average Value ◽  
Semiconductor Behavior ◽  
Ion Substitution ◽  
Diffraction Patterns ◽  
Increasing Temperature

Nominal compositions of Ni x Ti 1-x Fe 2 O 5-δ (x = 0, 0.2, 0.4, 0.6, 0.8 and 1) were prepared by a solid state reaction using stoichiometric amounts of Fe 2 O 3/ TiO 2 system and NiO as a dopant. The effects of small substitution of Ni ions on the electrical and structural properties were studied for the above system. The X-ray diffraction patterns revealed that the ferroelectric phase of iron titanate and the spinel ferrite phase of Ni -ferrite having a single phase at x = 0 and 1, respectively. The substitution of Ni ions increases the average value of lattice constant aav. Solid–solid interaction took place between the ternary oxides at 1200°C for 4 h yielding a new phase of NiTiO 3. The presence of the three phases was confirmed by X-ray diffraction technique. The resultant compositions have nanocrystallites with average crystalline size "D av " in the range 100–300 nm. The DC electrical resistivity ρ, Curie temperature TC and activation energies for electric conduction around TC region increase as Ni ion substitution increases. The ferrite samples have a semiconductor behavior where electrical resistivity ρ decreases on increasing temperature. The activation energy for electrical conduction was affected by both the ratio "ferroelectric/ferrite" and the position of the Curie temperatures in the compositions depending on the ( Ni , Ti ) to Fe ratio.

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