scholarly journals Structure analysis of electromagnetic waves absorbing material a lanthanum manganite system of (La0.8Ba0.2)(Mn(1-x)/2ZnxFe(1-x)/2)O3

2021 ◽  
Vol 1751 ◽  
pp. 012069
Author(s):  
L Rumiyanti ◽  
I Wandira ◽  
W A Adi ◽  
Junaidi ◽  
S Sembiring
Keyword(s):  
Structure Analysis ◽  
Electromagnetic Waves ◽  
Lanthanum Manganite ◽  
Absorbing Material

Effect of Lanthanum Substituted CoFe2-xLaxO4 on Change of Structure Parameter and Phase Formation

2020 ◽  
Vol 855 ◽  
pp. 70-77
Author(s):  
Akmal Johan ◽  
Ari Adi Wisnu ◽  
Fitri Suryani Arsyad ◽  
Dedi Setiabudidaya
Keyword(s):  
Magnetic Material ◽  
Magnetic Properties ◽  
Electromagnetic Waves ◽  
Earth Metal ◽  
Particle Morphology ◽  
Metal Elements ◽  
Elementary Analysis ◽  
Resonance Domain ◽  
Orbital Configuration ◽  
Absorbing Material

In this research, CoFe2-xLaxO4-based smart magnetic material has been developed which will be applied as a microwave absorbing material. This smart magnetic material is an artificial advanced material which has properties such as electromagnetic waves so that it is able to respond to the presence of microwaves through the mechanism of spin electron resonance and wall resonance domain. This smart magnetic material consists of a combination of rare earth metal elements (spin magnetic in the f orbital configuration) and transition metal elements (spin magnetic in the d orbital configuration) with a semi-hard magnetic structure. This semi-hard is a characteristic of magnetic properties which is between hard magnetic and soft magnetic properties. This characteristic of the semi-hard magnetic properties is needed so that this material has the ability to absorb microwaves. Substitution of lanthanum into cobalt ferrite CoFe2-xLaxO4 for La3+ (x = 0 - 0.8) has been synthesized using the solid reaction method through mechanical deformation techniques. The refinement result of X-ray diffraction shows that the sample contains 2 phases with increasing of x compositions. Particle morphology and elementary analysis were observed respectively by using a scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS). It was concluded that the effect of La substitution on CoFe2-xLaxO4 resulted in changes in the crystal structure parameters and phase transformation as a function of composition.

Microwave Properties of Composite Ba0.5Sr0.5Fe11.7Mn0.15Ti0.15O19/La0.7Ba0.3MnO3 Material

2014 ◽  
Vol 896 ◽  
pp. 440-443 ◽  
Author(s):  
Viktor Vekky Ronald Repi ◽  
Azwar Manaf ◽  
Bambang Soegiono
Keyword(s):  
Composite Materials ◽  
Ball Mill ◽  
Composite System ◽  
Lanthanum Manganite ◽  
Strontium Hexaferrite ◽  
Frequency Range ◽  
Crystalline Materials ◽  
Barium Strontium ◽  
Wide Range ◽  
Absorbing Material

Mn-Ti substituted Barium - Strontium Hexaferrite and Barium – Lanthanum Manganite both well established materials which have been shown poses microwave absorbtion properties. As the properties of composite system are a composition sensitive, composite materials must be properly designed to meet a specific application. In this paper, we report our recent investigation on microwave absorbtion properties of composite Ba0.5Sr0.5Fe11.7Mn0.15Ti0.15O19/La0.7Ba0.3MnO3system. Composite components respectively Ba0.5Sr0.5Fe11.7Mn0.15Ti0.15O19and La0.7Ba0.3MnO3were prepared through mechanical alloying route employing a planetary ball mill for 20 hrs. The two milled powders were sintered at a temperature 1100 °C for 10 hours to ensure the crystallization towards fully crystalline materials. Composites with 2 different compositions were studied by FTIR and VNA from which results were compared with that of each component. Results of the investigation concluded that, the composite of Ba0.5Sr0.5Fe11.7Mn0.15Ti0.15O19/La0.7Ba0.3MnO3system is a good microwave absorbing material in the frequency range 9 GHz-15 GHz, particularly, sample with coded A03B07 has a wide range frequencies absorption.

scholarly journals SYNTHESIS AND CHARACTERIZATION OF CoTi(1-X)Mn(X)O3 AS A RADAR ABSORBING MATERIAL

2020 ◽  
Vol 6 (1) ◽  
pp. 1
Author(s):  
Maspin Apit ◽  
Romie Oktovianus Bura ◽  
Wisnu Ari Adi ◽  
Raden Andhika Ajiesastra
Keyword(s):  
Electromagnetic Waves ◽  
Band Frequency ◽  
Radar Absorbing Material ◽  
Radio Detection ◽  
In Doping ◽  
X Band ◽  
Milling Method ◽  
Absorbing Material ◽  
Average Size ◽  
Radar Wave

<div><p class="Els-history-head">To avoid detection from Radio Detection and Ranging (Radar), one of the efforts is to use Radar absorbing material. One of the Radar wave absorbing materials is Perovskite CoTiO<sub>3</sub>. This Paper investigated the ability of CoTi<sub>(1-x)</sub>Mn<sub>(x)</sub>O<sub>3 </sub>to absorb the Radar wave. CoTi<sub>(1-x)</sub>Mn<sub>(x)</sub>O<sub>3</sub> with variations x = 0, 0.01, 0.02, and 0.03 have been successfully synthesized using the mechanical milling method. The XRD pattern shows that the sample formed was single phase CoTiO<sub>3</sub>. Surface morphology resulting from measurements with SEM shows homogeneous particles and an average size of 200 nm. The results of measurements with VNA at X-band frequency (8.20 GHz - 12.4 GHz) show that the absorption ability of electromagnetic waves from CoTiO<sub>3</sub> increases with the increase in doping from Mn<sup>4+</sup>. Maximum results obtained at the composition x=0.03 (CoTi<sub>0.97</sub>Mn<sub>0.03</sub>O<sub>3</sub>) with a reflection loss (RL) value is -14.56 dB (%Abs is 81.3%) at a frequency of 9.96 GHz. This result proves that CoTi<sub>(1-x)</sub>Mn<sub>(x)</sub>O<sub>3</sub> can be used as a Radar absorbing material at X-band frequency.</p></div>

Fabrication of electromagnetic waves absorbing material by ink-jet printing method

2020 ◽  
Vol 31 (9) ◽  
pp. 7093-7099 ◽  
Author(s):  
Mohammad Momeni-Nasab ◽  
Seyed Mansour Bidoki ◽  
Mohsen Hadizadeh ◽  
Masoud Movahhedi
Keyword(s):  
Electromagnetic Waves ◽  
Ink Jet Printing ◽  
Ink Jet ◽  
Absorbing Material ◽  
Jet Printing ◽  
Printing Method

scholarly journals Methods for Substantiating the Electrodynamic and Design Parameters of Absorbing Materials of Waveguide Type

2020 ◽  
pp. 272-283
Author(s):  
Andrey A. Ivenskiy
Keyword(s):  
Electromagnetic Waves ◽  
Periodic Structures ◽  
Dielectric Permeability ◽  
Wave Impedance ◽  
Metal Substrate ◽  
Design Parameters ◽  
Material Surface ◽  
Infinite Layer ◽  
Absorbing Material ◽  
Waveguide Type

The paper considers the issues related to the microwave diffraction on periodic structures of waveguide type. An approach used for assessing the reflective characteristics of absorbing material is proposed. This approach is based on the assumption that in accordance with the energy conservation law, the entire power of the incident microwave radiation on the absorbing material is distributed into two components. One of them characterizes electromagnetic radiation reflection from material surface and is determined through wave impedance at the interface “medium – absorbing material”, and the other, obeying the law of electromagnetic waves diffraction on nonperfectly conducting closed surfaces of waveguide type, propagates into the lattice, then it is partially absorbed in the bulk of the material and reflected from the object (metal substrate), after which it is summed with the first component at the output. A feature of the proposed technique is the design ratios, allowing to determine rational values of dielectric permeability of material, lattice elements conductivity as well as the period and thickness of the lattice which enable to achieve “a semi-infinite layer” at which the minimum value of material reflection coefficient is observed and its no longer depends on the presence or absence of an object (metal substrate)

Seti Space Missions

1997 ◽  
Vol 161 ◽  
pp. 761-776 ◽  
Author(s):  
Claudio Maccone
Keyword(s):  
Electromagnetic Waves ◽  
Space Missions ◽  
Gravitational Lens ◽  
The Sun ◽  
Space Antenna ◽  
Focal Distance ◽  
Large Space ◽  
The Earth ◽  
Space Antennas ◽  
New Space

AbstractSETI from space is currently envisaged in three ways: i) by large space antennas orbiting the Earth that could be used for both VLBI and SETI (VSOP and RadioAstron missions), ii) by a radiotelescope inside the Saha far side Moon crater and an Earth-link antenna on the Mare Smythii near side plain. Such SETIMOON mission would require no astronaut work since a Tether, deployed in Moon orbit until the two antennas landed softly, would also be the cable connecting them. Alternatively, a data relay satellite orbiting the Earth-Moon Lagrangian pointL2would avoid the Earthlink antenna, iii) by a large space antenna put at the foci of the Sun gravitational lens: 1) for electromagnetic waves, the minimal focal distance is 550 Astronomical Units (AU) or 14 times beyond Pluto. One could use the huge radio magnifications of sources aligned to the Sun and spacecraft; 2) for gravitational waves and neutrinos, the focus lies between 22.45 and 29.59 AU (Uranus and Neptune orbits), with a flight time of less than 30 years. Two new space missions, of SETI interest if ET’s use neutrinos for communications, are proposed.

200kv superconducting cryo electron microscope

1987 ◽  
Vol 45 ◽  
pp. 642-643
Author(s):  
M. Iwatsuki ◽  
Y. Kokubo ◽  
Y. Harada ◽  
J. Lehman
Keyword(s):  
Electron Microscope ◽  
Structure Analysis ◽  
Organic Materials ◽  
Strong Interactions ◽  
Specimen Preparation ◽  
Great Effort ◽  
Electron Microscopic ◽  
Crystal Fields ◽  
Special Skill ◽  
Long Time

In recent years, the electron microscope has been significantly improved in resolution and we can obtain routinely atomic-level high resolution images without any special skill. With this improvement, the structure analysis of organic materials has become one of the interesting targets in the biological and polymer crystal fields.Up to now, X-ray structure analysis has been mainly used for such materials. With this method, however, great effort and a long time are required for specimen preparation because of the need for larger crystals. This method can analyze average crystal structure but is insufficient for interpreting it on the atomic or molecular level. The electron microscopic method for organic materials has not only the advantage of specimen preparation but also the capability of providing various information from extremely small specimen regions, using strong interactions between electrons and the substance. On the other hand, however, this strong interaction has a big disadvantage in high radiation damage.

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