Article Per Year (5 Year)
p-Index From 2021 - 2026
0.444
P-Index
This Author published in this journals
All Journal Rekayasa Mesin Science and Technology Indonesia
Nehan, Phahul Zhemas Zul
Unknown Affiliation
Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Environmental Science Materials Science & Nanotechnology Mechanical Engineering Physics

Published : 2 Documents Claim Missing Document
Claim Missing Document
Check
Articles

Found 2 Documents
Search

 1 
Analysis of Structure, Morphology, Magnetic Properties, and Microwave Absorption of Lanthanum Orthoferrite (LaFeO3) Naibaho, Marzuki; Widakdo, Januar; Kurniawan, Budhy; Nehan, Phahul Zhemas Zul; Vitayaya, Okvarahireka; Novita; Ramlan; Adi, Wisnu Ari; Ginting, Masno
Science and Technology Indonesia Vol. 9 No. 4 (2024): October
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.2024.9.4.851-856

Abstract

LaFeO3 has been prepared using the solid-state reaction method with High Energy Milling (HEM). The preparation of LaFeO3 was carried out using stoichiometric calculations. Based on the XRD measurement results, single-phase LaFeO3 with an orthorhombic crystal structure was obtained. From the SEM results, the morphology of LaFeO3 is uniform, and the EDS results show the weight percentage of La, Fe, and O elements are 49.74, 21.08, and 29.18 wt%, respectively. VSM LaFeO3 results show magnetic saturation, remanence, and coercivity are 0.24 emu/g, 0.02 emu/g, and 853.38 Oe, respectively, and the absorption of LaFeO3 is -7.40 dB at a frequency of 6.02 GHz with a LaFeO3 sample thickness of 1.5mm.
Tailoring Phase Transformation of Calcium-Zirconia on Structural ond Mechanical Properties Setopratama, Andyan Rafi; Nehan, Phahul Zhemas Zul; Latief, Faried; Wismogroho, Agus Sukarto; Triwikantoro, Triwikantoro; Sulistijono, Sulistijono; Widyastuti, Widyastuti
Jurnal Rekayasa Mesin Vol. 17 No. 2 (2026)
Publisher : Jurusan Teknik Mesin, Fakultas Teknik, Universitas Brawijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21776/

Abstract

Developing sustainable stabilizers for zirconia extracted from natural zircon sand is essential to reduce reliance on conventional commercial additives while improving resource utilization. This study investigated the effects of calcium concentration and calcium source on the structural evolution and mechanical properties of zirconia synthesized via an alkali fusion–coprecipitation process. Seven samples were synthesized using eggshell-derived and commercial calcium dopants at concentrations of 0–1.5 mol%. Raman spectroscopy confirmed the dissociation and recombination of Si–O bonds in the ZrSiO4 lattice and the formation of ZrO2, while X-ray fluorescence verified a ZrO2 purity of 85.712 wt.%. X-ray diffraction revealed that calcium doping expanded the lattice parameter (c-axis: 5.100–5.180 Å), increased tetragonality (c/a up to 1.4420), reduced microstrain (109.2 × 10-4 to 51.8 × 10-4), increased crystallite size (7.4–8.3 nm), and nonlinearly enhanced the tetragonal phase fraction, reaching 7.2 wt.% at 1.0 mol% commercial calcium before declining at higher concentrations. Sintering at 1400 °C for 3 h completely transformed the tetragonal phase into the monoclinic phase. Eggshell-derived calcium at 0.5 mol% exhibited the best density (4.055 g/cm3), lowest porosity (19.447%), and greatest Vickers hardness (142.2 HV), comparable to commercial calcium. These findings suggest that calcium derived from eggshells is a viable and sustainable alternative stabilizer for zirconia ceramics, whilst also promoting the utilization of waste.
Co-Authors Agus Sukarto Wismogroho, Agus Sukarto Budhy Kurniawan Januar Widakdo Latief, Faried Masno Ginting Naibaho, Marzuki Novita Ramlan Setopratama, Andyan Rafi Sulistijono Sulistijono Triwikantoro Triwikantoro Vitayaya, Okvarahireka Widyastuti Widyastuti Wisnu Ari Adi