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Synthesis and Characterization of Perovskite Manganate Based on La0.7Ca0.3MnO3 with Ni and Ti doping as Microwave Absorber Material Saptari, Sitti Ahmiatri; Mar’ah, Mufidatul; Taryana, Yana; Sudrajat, Nanang
Science and Technology Indonesia Vol. 9 No. 3 (2024): July
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26554/sti.2024.9.3.577-585

Research has been carried out on the effect of Ni and Ti doping on the microwave absorption properties of the perovskite manganate material La0.7Ca0.3Mn1-xNix/2Tix/2O3 (LCMNTO) with variations x = 0; 0.03; 0.05; and 0.1, which were synthesized by the sol-gel method. The effect of Ni and Ti doping on the structure, grain size, magnetic properties, and microwave absorption properties were investigated in detail by various analytical methods. XRD (x-ray diffraction) characterization showed that the material La0.7Ca0.3Mn1-xNix/2Tix/2O3 has a single phase with an orthorhombic crystal system. The SEM (scanning electron microscope) results showed a tendency to decrease in grain size when the composition of Ni and Ti dopants began to increase. VSM (vibrating sample magnetometer) characterization shows that La0.7Ca0.3Mn1-xNix/2Tix/2O3 is a soft magnet with magnetic properties that decrease with increasing Ni and Ti dopant composition. The characterization of VNA (vector network analyzer) in the 8-12 GHz shows that the highest ability to absorb microwaves is 98% at 8.24 GHz, and there is an addition of absorption areas point and widening of the absorption bandwidth. Thus, the material La0.7Ca0.3Mn1-xNix/2Tix/2O3 has the potential to become a microwave absorber material.

EXPERIMENTAL AND COMPUTATIONAL STUDY OF NITROGEN-DOPED TiO2 AS A PHOTOELECTRODE Saptari, Sitti Ahmiatri; Yuniarti, Elvan; Loua, Lamin Rene
Spektra: Jurnal Fisika dan Aplikasinya Vol. 8 No. 2 (2023): SPEKTRA: Jurnal Fisika dan Aplikasinya, Volume 8 Issue 2, August 2023
Publisher : Program Studi Fisika Universitas Negeri Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21009/SPEKTRA.082.03

TiO2 has been widely used as a dye-sensitized solar cell (DSSC) photoelectrode, and attempts have been made to improve the performance of the photoelectrode by adding doping. This study aims to synthesize nitrogen (N) doped TiO2 as a photoelectrode. The research was carried out experimentally and computationally using X-Ray Diffraction (XRD) test equipment, Fourier Transform Infra-Red (FTIR), and quantum espresso software using the Density Functional Theory (DFT) method. XRD results showed that TiO2 has an anatase phase, and variations in the addition of nitrogen (doped N) of 10% w/w, 20% w/w, and 30% w/w did not produce a phase change. The FTIR results of N-doped TiO2 and TiO2 provide information on the functional groups of the samples. The wave number absorption area 1626 cm-1 indicates the presence of N-H bonds with a bending vibration mode. In addition, it can be seen that there is an N-H bond with a stretching vibration mode at wave number 3436 cm-1. Computational calculations searched the band gap energy of each variation of N doping, and each obtained was 3.2 eV; 2.54 eV; 2.35 eV; and 1.64 eV. The results of this study indicate that the N-doped TiO2 photoelectrode is expected to produce better DSSC efficiency because the addition of N-doped to TiO2 causes a decrease in the bandgap energy. The N doping effect causes a new energy level. The new energy level must be positioned close to the existing valence and conduction bands. As a result, the energy required for electrons to transition from the valence band to the conduction band is reduced, effectively reducing the energy gap between the two. This change in electronic structure facilitates more effortless movement of electrons, driving increased conductivity.

A-Site Doped in Perovskite La(1-x)Bax/2Srx/2Mn0.4Ti0.6O3 (x = 0, 0.1, and 0.3) for Absorbing Microwave Material Saptari, Sitti Ahmiatri; Hapitanur, Dinda; Taryana, Yana; Sudrajat, Nanang; Rahman, Ikhwan Nur; Nanto, Dwi
Jurnal Penelitian Fisika dan Aplikasinya (JPFA) Vol. 13 No. 2 (2023)
Publisher : Universitas Negeri Surabaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26740/jpfa.v13n2.p106-118

Microwave radiation can have harmful effects on our bodies. With increased exposure due to online activities, it is essential to use absorber materials like perovskite manganate to reduce radiation. In this study, perovskite manganate La(1-x)Bax/2Srx/2Mn0.4Ti0.6O3 (x = 0, 0.1, and 0.3) was synthesized using the sol-gel method. X-ray diffraction (XRD) analysis revealed that the two samples were multi-phased, LaMnO3 and La2Ti2O7, and were formed, exhibiting a rhombohedral crystal structure (R -3 c). Morphological characterization of the sample surface using a Scanning Electron Microscope (SEM) showed that as doping increases, the grain size decreases from 282.02 to 245.63 nm at x=0 and x=0.3, respectively. This result implies that doping leads to more uniform grain distribution and enhanced grain refinement. Characterization via Vibrating Sample Magnetometer (VSM) revealed that the maximum saturation value, 0.79 emu/g, was attained when x = 0. This sample exhibits soft magnetic properties, as evidenced by its coercivity (Hc) value of < 1kOe. Results from the Vector Network Analyzer (VNA) indicate that the absorption capacity of La(1-x)Bax/2Srx/2Mn0.4Ti0.6O3 increases, with a maximum reflection loss value of -25.5 dB with 1.5 mm thickness. Consequently, La(1-x)Bax/2Srx/2Mn0.4Ti0.6O3 demonstrates potential as a microwave absorber material.

Dye Sensitized Solar Cells with X% Cu-TiO2 Photoelectrode Sensitized from Syzygium malaccense Fajriah, Nurul; Yuniarti, Elvan; Saptari, Sitti Ahmiatri
Jurnal Fisika dan Aplikasinya Vol 20, No 1 (2024)
Publisher : Lembaga Penelitian dan Pengabdian Kepada Masyarakat, LPPM-ITS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j24604682.v20i1.16611

Abstract: Dye Sensitized Solar Cell preparation with x% Cu-TiO2 photoelectrode sensitized from Jamaica guava leaf dye (Syzygium malaccense) has been successfully made. This DSSC composed of x% Cu- TiO2 Photoelectrode synthesized by the doctor blading method with variation concentration Cu dopant at 0%, 1%, and 5%. Sensitizer (dye) made with technique maceration; electrolyte solution used an iodine solution, counter electrode with a carbon layer made from a candle flame; all the components are then arranged like a sandwich. The layers were characterized by X-ray diffraction to determine the phase, structure, and crystal size. X-ray diffraction characterization was carried out on all x% Cu-TiO2 layers. X-ray diffraction results show that has identified TiO2 anatase phase compound with a tetragonal crystal structure and has an average crystal size obtained from calculations using the Williamson Hall method for 0%, 1%, and 5% Cu doping fractions respectively are 60.28 nm, 43.32 nm, and 53.32 nm. UV-Vis's spectrophotometric characterization was carried out to determine the optical properties of the dye, and the results showed that Jamaica guava leaf dye has light absorption at a wavelength between 400-700 nm with a band gap energy of 1.728 eV. Furthermore, the current-voltage (IV) characterization was carried out to determine the efficiency of the solar cell. Based on the research results, the addition of Cu dopants as Photoelectrode can increase the efficiency of DSSC at a certain concentration. The highest efficiency achieved is 0.0036 % at 1% Cu doping concentration.

Synthesis and Characterization of Activated Carbon From Biomass Waste as A Microwave Absorber Material Nuras, Muhammad Ishaq; Saptari, Sitti Ahmiatri; Tjahjono, Arif; Priambodo, Danang Pamungkas; Haiqal, Amanda
Al-Fiziya: Journal of Materials Science, Geophysics, Instrumentation and Theoretical Physics AL-FIZIYA JOURNAL OF MATERIALS SCIENCE, GEOPHYSICS, INSTRUMENTATION AND THEORETICAL PHYSICS VOL.7, N
Publisher : Physics Study Programme, Faculty of Science and Technology UIN Syarif Hidayatullah Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15408/fiziya.v7i1.41310

Excessive use of electronic technology can result in harmful radiation and electromagnetic interference, which pose risks to human health. To address this issue, researchers developed a material designed to absorb electromagnetic waves. The study focused on synthesizing and characterizing activated carbon derived from biomass waste, including water hyacinth, melinjo seed shells, and chicken eggshells, with the goal of reducing electromagnetic wave interference. The research process involved several key steps: washing the biomass materials, followed by carbonization, activation using a 65% KOH solution, and subsequent characterization of the material. The tests revealed that the activated carbon possessed a porous structure, which is essential for its absorption capabilities. The surface areas measured were 4.378 m²/g for water hyacinth, 2.518 m²/g for melinjo seed shells, and 2.992 m²/g for chicken eggshells. These surface areas are indicative of the material's potential effectiveness. Additionally, the microwave absorption capacities of the activated carbon were recorded as -18.342 dB for water hyacinth, -13.326 dB for melinjo seed shells, and -12.484 dB for chicken eggshells. These findings suggest that the activated carbons are highly effective as microwave absorber materials, with an absorption efficiency ranging between 94% and 98%.Excessive use of electronic technology can result in harmful radiation and electromagnetic interference, which pose risks to human health. To address this issue, researchers developed a material designed to absorb electromagnetic waves. The study focused on synthesizing and characterizing activated carbon derived from biomass waste, including water hyacinth, melinjo seed shells, and chicken eggshells, with the goal of reducing electromagnetic wave interference. The research process involved several key steps: washing the biomass materials, followed by carbonization, activation using a 65% KOH solution, and subsequent characterization of the material. The tests revealed that the activated carbon possessed a porous structure, which is essential for its absorption capabilities. The surface areas measured were 4.378 m²/g for water hyacinth, 2.518 m²/g for melinjo seed shells, and 2.992 m²/g for chicken eggshells. These surface areas are indicative of the material's potential effectiveness. Additionally, the microwave absorption capacities of the activated carbon were recorded as -18.342 dB for water hyacinth, -13.326 dB for melinjo seed shells, and -12.484 dB for chicken eggshells. These findings suggest that the activated carbons are highly effective as microwave absorber materials, with an absorption efficiency ranging between 94% and 98%.

Microwave Absorption Potential of La0.7[X0.95Y0.05]0.3MnO3 with Dual-Doped Sites {XY = (Ca,Ba), (Ca,Sr), and (Sr,Ba)} Apriatin, Apriatin; Saptari, Sitti Ahmiatri; Tjahjono, Arif
Al-Fiziya: Journal of Materials Science, Geophysics, Instrumentation and Theoretical Physics AL-FIZIYA JOURNAL OF MATERIALS SCIENCE, GEOPHYSICS, INSTRUMENTATION AND THEORETICAL PHYSICS VOL.7, N
Publisher : Physics Study Programme, Faculty of Science and Technology UIN Syarif Hidayatullah Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15408/fiziya.v7i2.47935

The technology in the field of electronic devices is currently advancing in line with the increasing usage by humans. This continuous and growing usage also increases the amount of microwave radiation generated. This leads to wave interference that can disrupt the functionality of application devices. Absorbing materials are a type of material that functions as a microwave absorber. This study engineered lanthanum manganate material, specifically La0.7[X0.95 Y0.05]0.3MnO3 {XY = (Ca,Ba), (Ca,Sr), and (Sr,Ba)}, synthesized using the sol-gel method. The X-Ray Diffraction characterization results showed that each sample has a single-phase orthorhombic structure with a space group of Pbnm (62). The Scanning Electron Microscope–Energy Dispersive Spectroscopy characterization revealed particle morphology with varying particle size distributions on a micro-scale. Based on Vibrating Sample Magnetometer results, the samples La0.7[Ca0.95Ba0.05]0.3MnO3 and La0.7[Ca0.95Sr0.05]0.3MnO3 exhibit paramagnetic properties, while La0.7[Sr0.95Ba0.05]0.3MnO3 exhibits superparamagnetic properties. Through Vector Network Analyzer characterization, it was found that lanthanum manganate doped with Ca, Ba, and Sr demonstrated high electromagnetic wave absorption capabilities, achieving an absorption rate of 97%–98% at frequencies of 10–10.5 GHz. Thus, La0.7[X0.95 Y0.05]0.3MnO3 {XY = (Ca,Ba), (Ca,Sr), and (Sr,Ba)} is a potential candidate as a microwave-absorbing material.

DAMAGE ANALYSIS OF INSULATED PIPES USING DIGITAL DETECTOR ARRAY DAN COMPUTED RADIOGRAPHY Tjahjono, Arif; Pratama, Elfriani Dita; Hanuarjie, Baskan; Saptari, Sitti Ahmiatri; Kumila, Biaunik Niski
Al-Fiziya: Journal of Materials Science, Geophysics, Instrumentation and Theoretical Physics AL-FIZIYA JOURNAL OF MATERIALS SCIENCE, GEOPHYSICS, INSTRUMENTATION AND THEORETICAL PHYSICS VOL.8, N
Publisher : Physics Study Programme, Faculty of Science and Technology UIN Syarif Hidayatullah Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15408/fiziya.v8i1.46385

The provision of insulation on the pipe functions to prevent heat transfer, but the provision of this insulation causes the pipe to be susceptible to damage due to oxidation. In this study, an analysis of damage to insulated pipes will be carried out using a Digital Detector Array (DDA), Computed Radiography (CR), and XRF. Based on the test results, it is known that the image quality using DDA with a voltage of 240 kV produces the most optimal contrast resolution. The results of the thickness dimension measurement using the DDA method on insulated pipes are 3.38 mm, and on insulated pipes with artificial defects are 4 mm. Compared with the CR method, the values are 3.02 mm and 3.94 mm, respectively. The smaller the difference, the more accurate. From the calculation of the ISee software, it is also known that the DDA method can detect a greater number of defects, namely 24, compared to the CR method, which has only 14. The results of the XRF test show that the insulated pipe includes low-carbon steel with a carbon content of 0.057% and 94% ferrum. This high ferrous content contributes to increased X-ray absorption, greatly affecting the images quality.

Synthesis and Characterization of Activated Carbon From Biomass Waste as A Microwave Absorber Material Nuras, Muhammad Ishaq; Saptari, Sitti Ahmiatri; Tjahjono, Arif; Priambodo, Danang Pamungkas; Haiqal, Amanda
Al-Fiziya: Journal of Materials Science, Geophysics, Instrumentation and Theoretical Physics AL-FIZIYA JOURNAL OF MATERIALS SCIENCE, GEOPHYSICS, INSTRUMENTATION AND THEORETICAL PHYSICS VOL.7, N
Publisher : Al-Fiziya: Journal of Materials Science, Geophysics, Instrumentation and Theoretical Physics

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15408/fiziya.v7i1.41310

Excessive use of electronic technology can result in harmful radiation and electromagnetic interference, which pose risks to human health. To address this issue, researchers developed a material designed to absorb electromagnetic waves. The study focused on synthesizing and characterizing activated carbon derived from biomass waste, including water hyacinth, melinjo seed shells, and chicken eggshells, with the goal of reducing electromagnetic wave interference. The research process involved several key steps: washing the biomass materials, followed by carbonization, activation using a 65% KOH solution, and subsequent characterization of the material. The tests revealed that the activated carbon possessed a porous structure, which is essential for its absorption capabilities. The surface areas measured were 4.378 m²/g for water hyacinth, 2.518 m²/g for melinjo seed shells, and 2.992 m²/g for chicken eggshells. These surface areas are indicative of the material's potential effectiveness. Additionally, the microwave absorption capacities of the activated carbon were recorded as -18.342 dB for water hyacinth, -13.326 dB for melinjo seed shells, and -12.484 dB for chicken eggshells. These findings suggest that the activated carbons are highly effective as microwave absorber materials, with an absorption efficiency ranging between 94% and 98%.Excessive use of electronic technology can result in harmful radiation and electromagnetic interference, which pose risks to human health. To address this issue, researchers developed a material designed to absorb electromagnetic waves. The study focused on synthesizing and characterizing activated carbon derived from biomass waste, including water hyacinth, melinjo seed shells, and chicken eggshells, with the goal of reducing electromagnetic wave interference. The research process involved several key steps: washing the biomass materials, followed by carbonization, activation using a 65% KOH solution, and subsequent characterization of the material. The tests revealed that the activated carbon possessed a porous structure, which is essential for its absorption capabilities. The surface areas measured were 4.378 m²/g for water hyacinth, 2.518 m²/g for melinjo seed shells, and 2.992 m²/g for chicken eggshells. These surface areas are indicative of the material's potential effectiveness. Additionally, the microwave absorption capacities of the activated carbon were recorded as -18.342 dB for water hyacinth, -13.326 dB for melinjo seed shells, and -12.484 dB for chicken eggshells. These findings suggest that the activated carbons are highly effective as microwave absorber materials, with an absorption efficiency ranging between 94% and 98%.

Microwave Absorption Performance of La0.7Sr0.3MnO3/AC Composite Material Based on Activated Carbon from Gnetum gnemon Seed Shell Priambodo, Danang Pamungkas; Saptari, Sitti Ahmiatri; Tjahjono, Arif; Manawan, Maykel T; Taryana, Yana; Hadiyawarman; Admi, Ratna Isnanita
Communications in Science and Technology Vol 10 No 2 (2025)
Publisher : Komunitas Ilmuwan dan Profesional Muslim Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21924/cst.10.2.2025.1727

The 5G internet network has been proven to facilitate daily life for people and render electronic devices such as smartphones as an integral component of people's daily routine. However, in conjunction with the ease of use, there is an issue of electromagnetic radiation. To cope with this issue, magnetic and dielectric composite microwave absorber materials have been undertaken. To address this, we investigated the limitations of activated carbon composite material from Gnetum gnemon seed shells (AC) on the microwave absorption ability of (La0.7Sr0.3MnO3)1-y/(AC)y. The composite material (La0.7Sr0.3MnO3)1-y/(AC)y (y = 0; 0.3; 0.5; 0.7) was synthesized through a stirring process with a 96% ethanol catalyst using La0.7Sr0.3MnO3 synthesized by sol-gel method and activated carbon material from Gnetum gnemon seed shell (AC) synthesized by chemical activation method. The XRD and SEM characterizations indicated a single-phase structure, with smaller crystals and particles that were uniformly distributed throughout the composite sample. The presence of activated carbon grains from Gnetum gnemon seed shells (AC) were observed between the La0.7Sr0.3MnO3 grains in the composite sample. The EDS results confirmed the material’s purity. VNA characterization demonstrated that (La0.7Sr0.3MnO3)1-y/(AC)y was capable of producing two reflection loss troughs with the largest absorption percentages recorded at 82.99% and 85.82% respectively within the frequency range of 8 – 12 GHz. This research highlights the significance of controlled composite composition in enhancing microwave absorption capability, particularly in perovskite-based composites with biomass-activated carbon, which holds a considerable promise for applications in electromagnetic wave attenuation and absorption technologies.

First-Principle Investigation of La0.7Ba0.3Mn(1-x)FexO3 Structural Properties Using CASTEP Saptari, Sitti Ahmiatri; Aulia, Sarah; Rizaldy, Ryan; Azhar, Anugrah
INDONESIAN JOURNAL OF APPLIED PHYSICS Vol 13, No 2 (2023): October
Publisher : Department of Physics, Sebelas Maret University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.13057/ijap.v13i2.77031

We conducted first-principles Density Functional Theory (DFT) calculations using the CASTEP software package to investigate the crystal structure and mechanical properties of Fe3+-doped La0.7Ba0.3MnO3 material at the Mn3+ site, with doping concentrations ranging up to 50%. Through geometry optimization, we simulated the X-ray diffraction (XRD) pattern. We observed that the doping of Fe did not result in a shift in the peak positions of the diffraction pattern. However, it led to an increase in intensity at the [012] peak and the splitting of peaks [104] and [110]. Regarding the mechanical properties, we examined the elastic constants and observed a reduction in the Bulk, Shear, and Young's modulus values. The Shear and Bulk modulus and Poisson's ratio indicated that La0.7Ba0.3Mn(1-x)FexO3 becomes less ductile with increased Fe3+ doping content. Furthermore, we performed calculations for the Debye temperature, which revealed a decrease in the thermal conductivity of the La0.7Ba0.3Mn(1-x)FexO3 material.

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