Yofentina Iriani
Jurusan Fisika FMIPA Universitas Sebelas Maret, 2Program Studi Fisika FKIP Universitas Sebeles Maret Jl. Ir. Sutami No 36A Surakarta

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STUDI PEMBALIKAN POLARISASI DAN MODEL HISTERISIS PADA MATERIAL LAPISAN TIPIS BARIUM STRONSIUM (Ba0,5 Sr 0,5TiO3 ) DIDADAH Pb, Mg dan Cu Yoga Raksa, Teguh; Hikam, Muhammad; Iriani, Yofentina
Jurnal Spektra Vol 15, No 1 (2014): Spektra: Jurnal Fisika dan Aplikasinya
Publisher : Jurnal Spektra

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Abstract

Switching phenomenon inBIST thin film will be studiedusing bulk ferroelectric material approach. Static and dynamic  approach will be formulated by combination of Landau – Devonshire (LD) and Landau – Kalatnikov (LK) equation to determined maximum and minimum of switching current. Hysteresis loop was developed using sinusoidal electrical field  response by variation in frequency and amplitude of electrical field to describe hysteresis model of BST. Keywords: Switching Phenomenon , Hysterisis Model, Landau Theory,BST
PELATIHAN PEMANFAATAN ALAT PERAGA BAGI GURU SD MUHAMMADIYAH DI SUKOHARJO DALAM MENGHADAPI ERA REVOLUSI INDUSTRI 4.0 Anwar, Fuad; Kusumandari, Kusumandari; Iriani, Yofentina; Yunianto, Mohtar
ADI WIDYA : JURNAL PENGABDIAN MASYARAKAT Vol 4, No 1 (2020): ADIWIDYA
Publisher : Lembaga Penelitian dan Pengabdian Masyarakat

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (485.6 KB) | DOI: 10.33061/awpm.v4i1.3135

Abstract

Community service activities for Muhammadiyah Elementary School Teachers in Polokarto Subdistrict, Sukoharjo Regency have been carried out. The background of this activity is the information obtained that the teachers in the school still use books and blackboards especially for subjects related to Science so that students become less creative and innovative thinking. activities carried out in the form of ongoing activities, namely training in the use of props style, motion and energy as many as 10 kits, presentation of the results of the practice of using props and the process of dissemination to students. The results obtained that all participants in understanding the teaching aids that have been trained, seen from the activeness of the participants, the ability of participants in the presentation and the results of dissemination to students in their respective schools
The Effect of Copper-Silver (Cu-Ag) Double Doping on ZnO Photoanode on Dye Sensitized Solar Cell (DSSC) Efficiency Berliani, Rhiska Aria; Haq, Fat Hana Rizqi; Ningrum, Eka Silvia; Lestari, Putri; Iriani, Yofentina; Nurosyid, Fahru
Jurnal Penelitian Fisika dan Aplikasinya (JPFA) Vol. 14 No. 2 (2024)
Publisher : Universitas Negeri Surabaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26740/jpfa.v14n2.p144-153

Abstract

A DSSC has a good performance seen from the ability of the photoanode to absorb sunlight. The use of photoanodes uses a semiconductor material, namely ZnO. However, in use, ZnO has the disadvantage of low optical and electrical properties, which results in low DSSC efficiency. So in this research, efforts are made to add Cu-Ag double doping to improve optical and electrical properties that will increase the efficiency of DSSC. ZnO/Cu-Ag photoanodes were prepared using the sol-gel spin coating method with doping variations of 0%, 1%, 2%, and 3%. Characterization was carried out using a UV-Vis spectrophotometer to see the absorption area and determine the band gap energy of the ZnO photoanode. I-V Keithley was used for current and voltage characterization to determine the conductivity of the ZnO photoanode and the efficiency of the DSSC. The results of the research show the effect of increasing the optical properties of ZnO photoanodes by decreasing the band gap energy along with the increase in doping concentration, namely 3.29 eV, 3.24 eV, 2.44 eV, and 2.40 eV. In addition, there is an increase in conductivity on the ZnO photoanode with the highest conductivity at doping concentration of 3% which is 0.1006 Ω-1m-1 with an increase of 6 times compared to the pure ZnO photoanode of 0.0163 Ω-1m-1. The improved optical and electrical properties of ZnO/Cu-Ag photoanodes have an impact on increasing the efficiency value of DSSC with the optimum efficiency achieved at 1% doping concentration of 0.0291% with an increase of 16 times compared to the use of pure ZnO photoanode of 0.00018%. The addition of Cu-Ag doping to ZnO improves the optical and electrical properties of the photoanode, enhancing DSSC efficiency with an optimum at 1% doping concentration.
Microstructure and Optical Properties Study of Nd-doped BiFeO3 (Ba1-xNdxFeO3) Films on Quartz Substrate Iriani, Yofentina; Sandi, Dianisa Khoirum; Nurmawanti, Rainisa; Budiawanti, Sri; Agustina, Elvinda Bendra
Jurnal Penelitian Fisika dan Aplikasinya (JPFA) Vol. 11 No. 2 (2021)
Publisher : Universitas Negeri Surabaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26740/jpfa.v11n2.p148-157

Abstract

Bismuth ferrite oxide (BFO), due to its remarkable properties, has become one of the most attractive multiferroic materials to be extensively studied. BFO doped with various materials, including Neodymium (Nd), could improve its properties that apply to numerous electronic devices. However, the studies related to the properties of Nd-doped BFO (Ba1-xNdxFeO3) thin films on a quartz substrate, especially the optical properties, are relatively scarce. This study aimed to investigate the microstructure and optical properties of the Nd-doped BFO (BNFO) as the variation of the Nd concentrations. The BNFO thin films with Nd concentrations of 0.05 (BNFO5); 0.1 (BNFO10); and 0.2 (BNFO20) have been deposited on the quartz substrates via the sol-gel method and using spin coating. The films were annealed at 600 °C for 1.5 h. The XRD result of the BNFO films revealed a single phase of BFO with a cubic structure. The lattice constants and volume cells of the films declined with more Nd. Meanwhile, the crystallite size and lattice strain changed due to the change in the Nd number. Additionally, the morphology images showed the pores on the films’ surface and the different film thicknesses of each BNFO film. From the optical characterization, the transmittance spectra of the BNFO films tended to rise as the more Nd amount doped, in which the BNFO20 had the highest transmittance. The BNFO10 had the highest refractive index, followed by the BNFO5 and BNFO20. Contrarily, the BNFO20 had the highest extinction coefficient and  spectra, followed by the BNFO5 and BNFO10. Further, the bandgap values of the BNFO5, BNFO10, and BNFO20 were 2.75, 2.85, and 2.64 eV, respectively. Accordingly, due to the highest Nd amount that most impacted its microstructure, the BNFO20 exhibited the lowest bandgap value compared to the other films that are good for photovoltaic applications.
Lanthanum-substituted Cobalt Ferrite Established by the Co-precipitation Process: Annealing Temperature Adjustment of Structural, Magnetic, and Dye Removal Characteristics Rahmawati, Ramadona; Musadewi, Adiana; Prasetya, Nurdiyantoro Putra; Suharno, Suharno; Budiawanti, Sri; Rahardjo, Dwi Teguh; Riyatun, Riyatun; Utari, Utari; Iriani, Yofentina; Nuryani, Nuryani; Purnama, Budi
Bulletin of Chemical Reaction Engineering & Catalysis 2023: BCREC Volume 18 Issue 4 Year 2023 (December 2023)
Publisher : Masyarakat Katalis Indonesia - Indonesian Catalyst Society (MKICS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.19638

Abstract

Co-precipitation process was used for the synthesis of lanthanum-substituted cobalt ferrite nanoparticles at several annealing temperatures (Ta), i.e., 200 °C, 300 °C, and 400 °C, for 5 h. XRD spectral depicted that the produced nanoparticles sample indicates a single phase of fcc inverse spinel conforming to ICDD No 22-1086. The crystallite size (D) calculation at the strongest peaks shows the increase in enhancing the Ta i.e., 18.99 nm, 19.90 nm, and 23.21 nm for 200 °C, 300 °C, and 400 °C, respectively. The FTIR results showed absorption band at the tetrahedral site, v1 ~575 cm−1 and the octahedral site, v2 ~474 cm−1. The absorption bands indicate that the lanthanum ions have successfully replaced the Fe3+ cations in the original cobalt ferrite structure. According to the hysteresis loop, the coercive field's (HC) magnitude falls from 700 Oe down to 550 Oe as Ta increases. This result is consistent with the anisotropy constant which decreased from 0.77×104 erg/cm3 to 0.56×104 erg/cm3. The obtained nanoparticles also showed superior performance (much larger than 95%) for dye removal of Congo red. Copyright © 2023 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).
Optimization of Silver Doping on Natural Dye Mixed Chlorophyll-Anthocyanin on The Efficiency of Dye Sensitized Solar Cells (DSSC) Pangesti, Desita Suci; Nurosyid, Fahru; Suryana, Risa; Iriani, Yofentina
Molekul Vol 20 No 3 (2025)
Publisher : Universitas Jenderal Soedirman

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20884/1.jm.2025.20.3.16687

Abstract

ABSTRACT. This study aimed to incorporate silver (Ag) in the mixture of chlorophyll-anthocyanin dyes to improve DSSC efficiency. This research evaluated the impacts of various natural dye modifications with different concentrations of Ag incorporation on the DSSC performance. Here, anthocyanin (A) was extracted from butterfly pea flowers, while chlorophyll (C) was extracted from spinach leaves. The two dyes were mixed with a volume ratio of (anthocyanin: chlorophyll) 1:3. From the ratio of anthocyanin: chlorophyll, the extraction of anthocyanin solution is 25% and chlorophyll is 75%. Ag was incorporated into the dye mixture (AC) with distinct concentrations of 0%, 3%, and 5%. The dyes were characterized using a UV-Vis spectrophotometer and Keithley I-V meter to investigate their optical and conductivity properties. The DSSC performance was assessed with a Keithley I-V meter. The yields exhibited that the Ag incorporation improved the absorbances and widened the absorption area of the AC dyes as compared to the single and mixed dyes without Ag addition. Further, the results demonstrated that Ag incorporation enhanced the conductivity of the AC dyes, showing that the values were 4.43×10⁻² (Ωm)⁻¹, 6.46×10⁻² (Ωm)⁻¹, and 8,21×10⁻² (Ωm)⁻¹ for 0%, 3%, and 5% Ag incorporation. Moreover, the conversion efficiency values obtained by DSSCs prepared with AC dyes, Ag-incorporated AC 3%, and Ag-incorporated AC 5% were 0.073%, 0.209%, and 0.111%, respectively that Ag incorporation could significantly advance the DSSC performance. This study found that the AC dyes incorporated with 3% Ag were he optimal composition to produce the optimal DSSC performance. Keywords: anthocyanin, chlorophyll, DSSC, dye, silver