Garuda - Garba Rujukan Digital

MODIFIKASI DISTRIBUSI MUATAN BERDASARKAN DISTRIBUSI FERMI-DIRAC DAN APLIKASINYA PADA HUKUM GAUSS Tiandho, Yuant; Maryana, Okky; Afriani, Fitri; Saefullah, Asep; Pardede, Indra
JST (Jurnal Sains dan Teknologi) Vol 9, No 2 (2020)
Publisher : Universitas Pendidikan Ganesha

Hukum Gauss merupakan salah satu hukum fundamental fisika, khususnya dalam kajian listrik. Salah satu variabel penting untuk dapat menggunakan hukum Gauss adalah kemampuan menentukan muatan yang terlingkupi permukaan Gauss. Umumnya, definisi distribusi muatan suatu objek didefinisikan oleh fungsi sepenggal (piecewise continuous function). Pada makalah ini diajukan suatu model distribusi muatan yang berlaku untuk di seluruh lokasi. Model tersebut disusun berdasarkan analogi dengan fungsi distribusi Fermi-Dirac. Model yang diajukan mengandung fungsi eksponensial yang terkait dengan radius benda dan dilengkapi dengan suatu parameter untuk menghindari munculnya lekukan kurva yang bersifat tidak fisis. Distribusi muatan tersebut dapat digunakan untuk simulasi menghitung muatan yang terlingkupi oleh permukaan Gauss dan menentukan medan listriknya. Beberapa kasus yang ditinjau adalah objek bola padat serta bola konsentris. Jika dibandingkan dengan distribusi muatan konvensional, distribusi muatan termodifikasi lebih sederhana dan dapat mereduksi algoritma proses komputasi. Oleh karena itu hal ini dapat dimanfaatkan dalam pembuatan media pembelajaran berbasis komputer yang ringkas dan sederhana.

Synthesis and Characterization of Titania-Rice Husk Silica Composites as Photocatalyst Posman Manurung; Rudy Situmeang; Ediman Ginting; Indra Pardede
Indonesian Journal of Chemistry Vol 15, No 1 (2015)
Publisher : Universitas Gadjah Mada

This article describes the synthesis of titania-silica composites by a sol-gel method using a mixture of silica of rice husk and titanium butoxide sols. Microstructures were examined at calcination temperature in the range of 500 to 700 °C, with temperatures interval of 50 °C. The sintered catalysts were subsequently tested for photodegradation of methylene blue (MB) under ultraviolet and sunlight rays. Physical characteristics were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM)/energy dispersive X-ray spectroscopy (EDS), and Brunauer-Emmett-Teller (BET). The XRD results did not show the presence of silica crystal phase in each sample. The results showed that the highest BET surface area of samples was obtained at the temperature of 650 °C. In sample calcined 500 °C, the activity of the catalyst on MB was relatively similar in both sunlight and ultraviolet rays.

Kajian Magnetoresistansi pada Nanopartikel Magnetite (Fe3o4) yang Dienkapsulasi dengan Polyethylene Glycole (PEG) dan Biomaterial dengan Sensor Lapisan Tipis Co/Cu Multilayer Berbasis Giant Magnetoresistance (GMR) (Halaman 13 s.d. 19) Ferawati Artauli Hasibuan1; Indra Pardede; Edi Suharyadi
Jurnal Fisika Indonesia Vol 19, No 56 (2015)
Publisher : Department of Physics Universitas Gadjah Mada

Telah dilakukan kajian magnetoresistansi (MR) pada nanopartikel magnetit (Fe3O4) yang dienkapsulasi dengan poliethilen glikol (PEG)-4000 dan biomolekul menggunakan sensor lapisan tipis berbasis giant magnetoresistance (GMR). Lapisan tipis yang digunakan adalah Si/Cr(5nm)/[Co(1,5nm)/Cu(x)]20/Cr(5nm) multilayer (x = 0,8; 0,9; dan 1,0 nm). Fenomena GMR dipengaruhi oleh variasi ketebalan lapisan tipis dan pelapisan nanopartikel Fe3O4 yang dienkapsulasi dengan PEG dan penambahan biomolekul yang mengganggu mobilitas momen magnetik material. Resistansi pada ketebalan lapisan tipis Cu 0,8; 0,9; dan 1,0 nm ketika H=0 masing-masing 3,7; 3,5; dan 2,7 Ohm dan ketika H=599,7 G masing-masing 3,5; 3,2; dan 2,3 Ohm. Nilai MR ketika lapisan tipis dilapisi nanopartikel Fe3O4, Fe3O4 yang dienkapsulasi dengan PEG, dan Fe3O4 yang dienkapsulasi dengan PEG dan penambahan biomolekul masing-masing mengalami perubahan yang berbeda. Perubahan nilai MR pada lapisan tipis multilayer sebelum dan setelah pelapisan nanopartikel menunjukkan bahwa lapisan tipis Co/Cu multilayer dapat diaplikasikan sebagai sensor medan magnet dan potensial sebagai biosensor.

HAWKING TEMPERATURE IN SCHWARZSCHILD BLACK HOLES WITH QUINTESSENCE DARK ENERGY Widiyani, Agustina; Sari, Ana Novita; Permanasari, Ikah Ning Prasetiowati; Satria, Eko; Pohan, Azrul Sulaiman Karim; Kesuma, Weni Ayu Puja; Pardede, Indra; Suroso, Agus
Indonesian Physical Review Vol. 8 No. 2 (2025)
Publisher : Universitas Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/ipr.v8i2.454

Black holes are thermodynamic objects that emit Hawking radiation near the event horizon of a black hole according to the theory of quantum gravity in curved space-time. This radiation is manifested as the temperature of a black hole, known as the Hawking temperature. According to black hole thermodynamics, the black hole horizon area corresponds to the entropy. The increase in the horizon area is predicted due to the influence of dark energy, which can push the horizon of the black hole away from its center, thus significantly affecting the radiation of the black hole. Here, we investigate the Hawking temperature of the Schwarzschild black hole under the effect of quintessence dark energy. The results show that the increase in quintessence reduces the horizon radius of the black hole and lowers its Hawking temperature, highlighting the direct relationship between dark energy and black hole dynamics.

Doping Strategies for Enhancing ZnO-Based Photodetectors: A Comprehensive Review Prayogo, Priyan; Eliyana, Ajeng; Satria, Eko; Pardede, Indra
Jurnal Ilmiah Pendidikan Fisika Al-Biruni Vol 14 No 1 (2025): Jurnal Ilmiah Pendidikan Fisika Al-Biruni
Publisher : Universitas Islam Negeri Raden Intan Lampung, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24042/jipfalbiruni.v14i1.26185

The performance of ZnO-based nanostructured photodetectors has garnered significant interest due to their potential for high sensitivity and fast response in ultraviolet and optoelectronic applications. This review aims to comprehensively analyze recent advancements in enhancing ZnO photodetector performance through single doping and codoping strategies. This study synthesizes findings from peer-reviewed research articles published over the past five years. The results indicate that specific dopants, such as F, Mg, Ti, and Co+Ni, significantly improve key performance parameters, including responsivity, sensitivity, and detectivity. Codoping approaches, particularly with In+Ga or Sn+Ti, exhibit synergistic effects that further enhance carrier mobility and reduce trap states, resulting in external quantum efficiencies exceeding 10⁹%. The review concludes that the careful selection and concentration of dopants, nanostructure design, and scalable fabrication methods are crucial for optimizing ZnO-based photodetectors. This work contributes by offering a structured synthesis of performance trends, identifying research gaps, and outlining future directions for developing high-performance and industry-ready ZnO photodetector technologies.

LANDSLIDE VULNERABILITY ANALYSIS BASED ON THE SEISMIC VULNERABILITY INDEX USING THE HVSR MICROTREMOR METHOD ON CLIFF AREAS IN HANURA VILLAGE, TELUK PANDAN DISTRICT, PESAWARAN REGENCY Permanasari, Ikah Ning Prasetiowati; Ba’asyir, Indi Nurazizah; Setiawan, Muhamad Ragil; Pardede, Indra; Monica, Yeli
Indonesian Physical Review Vol. 8 No. 3 (2025)
Publisher : Universitas Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/ipr.v8i3.484

Way Ratai Road in Pesawaran Regency connects tourist areas managed by the Lampung Provincial Government. This road has cliffs with steep slopes, which have the potential to cause landslides. This research is very important because Way Ratai road is the only access road to Pesawaran beach tourism which is the main tourist destination of Lampung Province. Moreover, Way Ratai road is also the only access road connecting to the provincial capital of Bandar Lampung. This research was conducted to determine the soil vulnerability to seismic vibration on two cliffs around Way Ratai Road, Teluk Pandan District, Pesawaran Regency. The method used was microtremor signal recording with the Horizontal Vertical to Spectral Ratio (HVSR) method to determine the amplification factor (), dominant frequency (), sediment thickness (H), and seismic vulnerability index (Kg). The first cliff's measurement and data processing results showed an amplification factor () value of 2.74 - 3.70, a dominant frequency () of 3.75 - 4.56 Hz, a sediment thickness (H) of 14.09 m, and a seismic vulnerability index (Kg) of 2.39 m²/s. On the second cliff, the results showed an amplification factor () value of 2.27 - 3.40, a dominant frequency () of 3.54 - 7.20 Hz, a sediment thickness (H) of 9.33 m, and a seismic vulnerability index (Kg) of 1.84 m²/s. In term of seismic vibration, both cliffs, prone to landslides, have high stability against seismic vibrations. In the event of a landslide on these two cliffs, the estimated slip surface on the first cliff would be translational, and the second cliff would be a combination of translational and slight rotational, with an estimated volume of soil that could potentially slide on the first cliff is 30,492.16 m³ and on the second cliff, it is 27,188.92 m³.

MODIFIKASI DISTRIBUSI MUATAN BERDASARKAN DISTRIBUSI FERMI-DIRAC DAN APLIKASINYA PADA HUKUM GAUSS Tiandho, Yuant; Maryana, Okky; Afriani, Fitri; Saefullah, Asep; Pardede, Indra
JST (Jurnal Sains dan Teknologi) Vol. 9 No. 2 (2020)
Publisher : Universitas Pendidikan Ganesha

Hukum Gauss merupakan salah satu hukum fundamental fisika, khususnya dalam kajian listrik. Salah satu variabel penting untuk dapat menggunakan hukum Gauss adalah kemampuan menentukan muatan yang terlingkupi permukaan Gauss. Umumnya, definisi distribusi muatan suatu objek didefinisikan oleh fungsi sepenggal (piecewise continuous function). Pada makalah ini diajukan suatu model distribusi muatan yang berlaku untuk di seluruh lokasi. Model tersebut disusun berdasarkan analogi dengan fungsi distribusi Fermi-Dirac. Model yang diajukan mengandung fungsi eksponensial yang terkait dengan radius benda dan dilengkapi dengan suatu parameter untuk menghindari munculnya lekukan kurva yang bersifat tidak fisis. Distribusi muatan tersebut dapat digunakan untuk simulasi menghitung muatan yang terlingkupi oleh permukaan Gauss dan menentukan medan listriknya. Beberapa kasus yang ditinjau adalah objek bola padat serta bola konsentris. Jika dibandingkan dengan distribusi muatan konvensional, distribusi muatan termodifikasi lebih sederhana dan dapat mereduksi algoritma proses komputasi. Oleh karena itu hal ini dapat dimanfaatkan dalam pembuatan media pembelajaran berbasis komputer yang ringkas dan sederhana.

FIRST-PRINCIPLES STUDY OF MAGNETIC ANISOTROPY ENERGY IN TWO-DIMENSIONAL FERROMAGNETIC CrI3 Mecci, Puke Lajaladita Litle; Monica, Annisa; Sinurat, Iin Riananda Br; Widiyani, Agustina; Rajak, Abdul; Pardede, Indra
Indonesian Physical Review Vol. 6 No. 1 (2023)
Publisher : Universitas Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/ipr.v6i1.191

First-principles calculations are increasingly crucial in searching for new materials with customized properties or new functionality. First-principles calculations are superior in speed and cost, and comparable to experiments in terms of accuracy. Two-dimensional (2D) ferromagnetism materials were successfully fabricated experimentally in atomic thin films of CrI3. 2D intrinsic ferromagnetism with perpendicular magnetic anisotropy energy (PMAE) is an encouraging applicant compatible with high-density magnetic storage applications. In this study, spin density functional calculations are investigated on the magnetic anisotropy energy (MAE) in 2D monolayer ferromagnetic CrI3 using a first-principles electronic structure calculation. We include the MAE part calculation from the magnetocrystalline anisotropy energy (MCAE) that comes from the spin-orbit coupling (SOC). In the present calculation, the MCAE part, in addition to a usual scheme of total energy (TE), was evaluated using a grand-canonical force theorem (GCFT) scheme. The MCAE of 2D monolayer ferromagnetic CrI3 is 1.7 meV/unit cell and verified it has an easy-axis perpendicular to the crystal plane, which is a good agreement with experimental measurement. In the latter scheme, employing GCFT, we evaluated atom-resolved, k-resolved, and atomic k-resolved analyses for MCAE can be performed. From the GCFT result, the Cr atom indicates that it is the primary origin of PMAE in the atom-resolved MCAE. The negative MCAE contribution is in points, and the positive MCAE is mainly placed at the line in the 2D first Brillouin zone. Our systematic calculation in this work may also help design an effective structure of monolayer CrI3 in new 2D material magnetic sensor and spintronic device designs.

Kajian First Principles tentang Sifat Elektronik dan Optik Semikonduktor ZnO dengan co-doping CoX (X = Cr, Mn, Ti, V) Prayoga, Harry; Rajak, Abdul; Widiyani, Agustina; Prayogo, Priyan; Musfiroh, Fatimatul; Pardede, Indra
Indonesian Physical Review Vol. 9 No. 1 (2026)
Publisher : Universitas Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/ipr.v9i1.530

The development of solar energy materials is essential for achieving the Sustainable Development Goals (SDGs). However, their performance is often limited by the electronic and optical properties of commonly used semiconductors. Unlike previous DFT studies mostly focused on non–transition metal dopants (e.g., Al, Ga), this work explores pristine ZnO, single cobalt (Co) doping, and CoX (X = chromium (Cr), manganese (Mn), titanium (Ti), and vanadium (V)) codoping to reveal how single and dual 3d-orbital interactions modify its electronic and optical behavior. This study investigates the effects of transition metal codoping CoX (X = Cr, Mn, Ti, V) on ZnO using Density Functional Theory (DFT) and DFT with Hubbard U correction (DFT+U) within the Generalized Gradient Approximation (GGA) to evaluate opto-electronic properties. The bandgap of pristine ZnO was calculated as ~0.80 eV with standard DFT, while ZnO-Co and ZnO-CoX exhibited zero bandgap with a flatband due to conduction band overlap with the Fermi level, indicating metallic behavior resulting from d-orbital contributions. DFT+U improved the pristine ZnO bandgap to ~1.08 eV, although Co-doped and CoX co-doped remained metallic. Orbital resolved analysis shows that Ti and V introduce states near the valence band, while Cr and Mn shift states deeper below the Fermi level, reflecting distinct d-orbital interactions. The theoretical band gaps underestimated experimental values due to strong electron correlation in ZnO. Optical analysis revealed that Co and CoX codoping shifts the absorption edge into the visible range and enhances the absorption intensity. The presence of dopants alters the electronic band structure and enhances optical absorption in the visible range, underscoring their effectiveness in engineering ZnO-based semiconductors for optimized optoelectronic responses.

Title

Found 9 Documents
Search

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Title Search

Found 9 Documents Search

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Title

Found 9 Documents
Search