Etty Marti Wigayati
Pusat Penelitian Fisika – LIPI Kawasan Puspiptek, Serpong, Tangerang

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PREPARATION AND CRYSTAL STRUCTURE CHARACTERIZATION OF Li(1+x)Mn2O4 Wigayati, Etty Marti
Jurnal Sains Materi Indonesia Vol 11, No 2 (2010): Februari 2010
Publisher : BATAN

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Li(1+x)Mn2O4 powder has been prepared with starting material of Li2CO3 as lithium source and MnO2 as manganese source. The preparation was done by powder metallurgy with varying Li addition in weight% of 5%, 10%, 15% and 30%. From Differential Thermal Analisys (DTA) data , it is revealed that calcination andsintering temperature are at 700 °C and 800 °C respectively. The characterisation results showed that all XRD patterns are similar for all composition of Li addition, but different in intensity. The diffraction data was analyzed by Rietveld method to get lattice parameter unit cell volume and crystal density. The lattice parameters reach optimum at 15% of Li addition. The cell volume increased could lead to better intercalation properties ofthis powder. Li ion can intercalate easier in this unit cell which make Li(1+x)Mn2O4 can be used as a cathodematerial.Keywords: Li(1+x)Mn2O4, Powder metallurgy method, Rietveld Analysis, Intercalation property.
Pengaruh Penambahan LiClO4 pada Pembuatan Komposit Anoda Grafit Bermatrik Polimer Prihandoko, Bambang; Wigayati, Etty Marti; Nurhayati, Nurhayati
Jurnal Fisika dan Aplikasinya Vol 3, No 1 (2007)
Publisher : Jurnal Fisika dan Aplikasinya

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Telah dilakukan penelitian tentang pengaruh penambahan LiClO4 pada pembuatan komposit anoda grafit bermatrik polimer. Komposit anoda grafit digunakan sebagai komponen baterai lithium. Komposit bermatriks polimer ini berbentuk lembaran tipis dan dapat diperoleh melalui proses pembuatan dengan metode tape casting yang menggunakan perangkat doctor blade. Ketipisan komposit anoda yang diperoleh berkisar sekitar 60 μm. Penambahan LiClO4 dilakukan dalam 0, 2, 4, 6, 8 dan 10%berat dari campuran bahan keramiknya, yaitu serbuk grafit dan karbon black. Penambahan ini ternyata tidak mempengaruhi pada proses pembuatan dan hasil lembarannya tetap tipis dan merata, tidak ada penggumpalan. Hasil pengamatan XRD menunjukkan keberadaan lithium perklorat hidrat yang disebabkan adanya reaksi antara uap air dan LiClO4. Komposisi nilai konduktivitaslistrik bernilai optimum diperoleh pada penambahan 4% LiClO4. Konduktivitas listrik komposit anoda meningkat dengan penambahan LiClO4 dan mencapai nilai optimum pada penambahan 4% LiClO4 yaitu sebesar 3,8 x 10−5 Scm−1 untuk nilai konduktivitas total dan sebesar 9,5 x 10−5 Scm−1 untuk nilai konduktivitas elektron.
KARAKTERISTIK SIFAT TERMAL, SIFAT LISTRIK DAN STRUKTUR KRISTAL DARI KERAMIK SIC DENGAN ADITIF CLAY Wigayati, Etty Marti; ., Muljadi
Urania Jurnal Ilmiah Daur Bahan Bakar Nuklir Vol 14, No 3 (2008): Juli 2008
Publisher : Urania Jurnal Ilmiah Daur Bahan Bakar Nuklir

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ABSTRAK Karakteristik Sifat Termal, Sifat listrik Dan Struktur Kristal Dari Keramik SiC Dengan Aditif Clay. Telah dilakukan penelitian pembuatan keramik SiC  dari bahan baku SiC teknis dan aditif clay. Komposisi clay adalah ( 0,1,3,4) % berat, dimana fungsi clay adalah sebagai perekat, dan tidak mempengaruhi sifat dari SiC. Sintering dilakukan pada temperatur 1300o C, 1400oC dan 1500o C. Struktur kristal yang terbentuk diamati dengan XRD, semua sampel yang di-sinterring pada berbagai temperatur menunjukan fasa dominan α-SiC dengan struktur kristal rhombohedral. Koefisien muai termal diamati dengan dilatometer, yang memberikan hasil  koefisien muai termal 5.62.10-6 C-1. Resistivitas terbesar pada aditif 4 % dan diukur pada rentang temperatur 75o C sampai 450o C adalah 1142 Ω.cm. Dari hasil penelitian ini keramik SiC menunjukkan sifat stabil sehingga dapat digunakan untuk refraktori dan komponen pada industri nuklir. Kata kunci: Sifat termal, sifat listrik, keramik SiC, bahan aditif,  clay dan   struktur kristal.   ABSTRACT CHARACTERISTIC OF THERMAL PROPERTY, ELECTRICAL PROPERTY AND CRYSTAL STRUCTURE OF SiC CERAMIC WITH ADDITIF CLAY ADDITION. Ceramic SiC has been made from raw materials  SiC technics and clay as additive.  Clay composition is  0, 1 , 3, 4 % weight, where function of clay is as a binder and it can not influence properties of SiC. Sintering was done at temperatures 1300o C, 1400oC and 1500o C. The crystal structure was observed by using XRD, and all sintered samples have dominant phase α-SiC with rhombohedral crystal structure. The coefficient of thermal expansion was measured by using Dilatometer, and value of coefficient of thermal expansion is 5.62.10-6 C-1. The highest resistivity value at 4 % additive and at temperature measurement between 75 – 450 C is 1142 Ω.cm. And the result of research shows that ceramic SiC is stable materials and can be used for refractory and also as components in nuclear industrials. Key word: Thermal property, electric property, SiC ceramic, additife matterial, clay,  crystal structure.
ANALISIS PENGARUH MECHANICAL MILLING MENGGUNAKAN PLANETARY BALL MILLING TERHADAP STRUKTUR KRISTAL DAN STRUKTUR MIKRO SENYAWA LiBOB Wigayati, Etty Marti; Purawiardi, Raden Ibrahim
Jurnal Sains Materi Indonesia Vol 16, No 3: APRIL 2015
Publisher : BATAN

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ANALISIS PENGARUH MECHANICAL MILLING MENGGUNAKAN PLANETARY BALL MILLING TERHADAP STRUKTUR KRISTAL DAN STRUKTUR MIKRO SENYAWA LiBOB. Telah dilakukan pembuatan senyawa Lithium bis Oksalat Borat (LiBOB) dari bahan baku LiOH, asam oksalat dan asam borat dengan metode reaksi padat padat. Serbuk yang dihasilkan dilanjutkan penghalusan menggunakan planetary ball milling dengan durasi milling di buat bervariasi (4 jam, 5 jam, 6 jam, 10 jamdan 13 jam). Serbuk LiBOB yang dihasilkan dianalisis menggunakan X-Ray Diffractometer (XRD) untuk mengetahui fasa yang terbentuk, struktur kristal dan ukuran kritalitnya. Hasil identifikasi senyawa LiBOB dengan XRD berupa pola difraksi kemudian dianalisismenunjukkan terbentuknya 2 fasa yaitu fasa LiB(C2O4)2 dan fasa LiB(C2O4)2.(H2O) dengan sistem kristal orthorhombic. Kerapatan atom paling kecil pada senyawa LiBOB dengan durasi milling 5 jam dan volum unit sel paling besar pada senyawa LiBOB dengan durasi milling 10 jam. Diameter ukuran kristalit berubah seiring dengan durasi milling, sedang regangan kisi terendah pada durasi milling 4 jam dan tertinggi pada durasi milling 5 jam. Durasi milling 5 jam adalah paling bagus dimana pada fasa ini memberikan ruang paling besar pada tiap unit sel dan regangan kisi paling besar sehingga dapat memudahkan ruang gerak transfer ion Li pada baterai Lithium. Senyawa LiBOB hasil sintesis mempunyai sistem kristal yang teratur. Tingkat keteraturan kristal yang dihasilkan ditunjukan dengan perhitungan indeks kristalinitas yang tinggi.
Microstructure Analysis of Synthesized LiBOB Wigayati, Etty Marti; Ratri, Christin Rina; Purawiardi, Ibrahim; Rohman, Fadli; Lestariningsih, Titik
Indonesian Journal of Chemistry Vol 15, No 3 (2015)
Publisher : Universitas Gadjah Mada

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Lithium bis (oxalate) borate or LiBOB is an active material used as the electrolyte for lithium battery application. LiBOB (LiB(C2O4)2) powder was prepared from LiOH, H2C2O4 and H3BO3. The employed method was solid state reaction. LiBOB powder produced from the reaction was then observed using SEM and TEM. Surface area was analyzed using Quantachrome Nova 4200e. From the analysis analyzed using XRD to identify the resulting phases, crystal structure, and crystallite size. The functional groups were analyzed using FT-IR. The particle morphology was result, it was seen that the resulted phases were C4LiBO8 and LiB(C2O4)2.H2O, the crystal structure was orthorhombic with space group Pbca and Pnma. From the particle morphology observation it was shown that micro pores were created irregularly. When the observation was deepened, nanopores with elongated round shape were seen within the micropores. The pore size was approximately 50–100 nm. The surface area, total pore volume, and average pore diameter of LiBOB powder was 88.556 m2/g, 0.4252 cm3/g, and 19.2 nm respectively.
PEMBUATAN BATAKO DARI ABU HASIL INSINERASI SAMPAH DOMESTIK DAN KARAKTERISASINYA Wigayati, Etty Marti; Muljadi, Muljadi
Jurnal Ecolab Vol 2, No 2 (2008): Ecolab : Jurnal Pemantauan Kualitas Lingkungan
Publisher : Pusat Penelitian dan Pengembangan Kualitas dan Laboratorium Lingkungan (P3KLL)

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Garbage problems are increasing day by day. Garbage problems may generate environmental pollution problemswith its impact are continued to be increased. One of the technology to destroy the garbage is by incinerator. Thestudy was trying to reuse the ash resulted from the incineration of garbage by incinerator which have an addedvalue. The ash composition was similar as clay, so the ash could be used as a raw material for making batako whichare the weight ratio between sand and comment was 3:1. Some of sand was substituted by ash from incinerator withcompositions of 0%, 10%, 20%, 25%, and 30%. All the raw materials were homogenously mixed, and then wereformed by casting and were dried in open air variation of time between 7 days and 28 days. The resulting dried batakowere characterized for its density as indicated the decreasing density was in line with the increasing of ash assubstituted and the drying time of 28 days gave result the bigger one. The porosity value decreased along with theash content and giving the smallest one after drying 28 days. The water absorption value will decreased along withthe increasing ash content and the longer time of drying process. The bending and compressive strength value weregrowing larger with increasing ash content, and by giving 25% ash, the compressive strength value became stabilized.Comparing to the existing batako market, batako using incinerator ash gave better quality.
PEMBUATAN NANOPAR TIKEL LixMn2O4 Wigayati, Etty Marti
Teknologi Indonesia Vol 32, No 2 (2009)
Publisher : LIPI Press

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LixMn2O4 nanoparticle has been prepared using Li2CO3 and MnO2 as starting materials. Firstly, Li2CO3 and MnO2 were mixed using solid state reaction, then the powder was calcinated at 700oC and sintered at 800oC. The resulted pouder was characterized using SEM, XRD, and EIS (Electrochemical Impedance Spectroscopy). Henceforth, LixMn2O4 powder was processed into nanoparticle size through milling process using PBM (Planetary Ball Milling) for 80 hour and ultrasonificator with power of 300 watt for 2 hour. The characterization was conducted again using SEM, XRD, PSA and EIS. The result shows that there is no diffraction pattern change after the milling process. Examination using SEM shows particle changes from needles to round shapes with smaller sizes. Diffraction analyzes using Rietveld method results in lattice parameter of 8.23454 , cell unit volume of 558.3647 3 and the crystal structure is cubic with space group of Fd-3m. The particle size of the final product is analyzed using Particle Size Analyzer (PSA) which results in the value of 178 nm in average diameter. The measurement of electrical impedance gives values of 2 M ohm (before milling) and 8 M ohm (after milling).
SINTESIS LiBOB DAN ANALISA STRUKTUR KRISTALNYA [Synthesis and Analysis Crystalline Structure LiBOB] wigayati, etty marti
Metalurgi Vol 30, No 2 (2015): Metalurgi Vol.30 No.2 Agustus 2015
Publisher : Pusat Penelitian Metalurgi dan Material - LIPI

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Litium Bis(Oksalato) Borat atau LiBOB merupakan garam Lithium yang saat ini mulai dikembangkan sebagai elektrolit alternatif untuk baterai Li-Ion. Elektrolit padat LiBOB dianggap lebih ramah lingkungan, LiBOB juga memiliki stabilitas panas yang cukup tinggi yakni sebesar 302 °C. Penelitian ini bertujuan untuk mensintesis LiBOB kemudian untuk mengetahui struktur kristalnyadan untuk mengetahui durasi sintering yang optimum. Sintesis LiBOB (Lithium bis oksalat borat)dilakukan melalui metoda solid state reaction. Bahan awal dicampur hingga homogen. Kalsinasi dilakukan pada temperatur 120 °C,ditahan selama 2 jam dilanjutkan dengan sintering pada temperatur 240 °C dengan penahanan dilakukan secara bervariasi yaitu 2 jam, 3 jam, dan 4 jam. Untuk mengetahui fasa yang terbentuk dilakukan karakterisasi dengan XRD. Dari hasil analisis XRD dapat diidentifikasi fasa yang terjadi pada waktu penahanan 2 jam masih muncul fasa dari bahan awal, LiBOB hidrat dan beberapa fasa impuritas. Pada waktu penahanan 3 jam terbentuk fasa LiBOB hidrat dan H3BO3. Pada penahanan 4 jam muncul fasa LiBOB dan LiBOB hidrat serta beberapa fasa impuritas. Sampel dengan penahanan 4 jam merupakan sampel yang paling optimum mendekati karakteristik kristal LiBOB dan LiBOB Hidrat pada sampel LiBOB komersial. Struktur kristal LiBOB yang terbentuk adalah orthorombik dengan nilai a, b, dan c sebesar 5.74 Å, 6,79 Å, dan 14,45 Å dengan sudut α = β = γ = 90°, grup ruangPnma (62), serta nilai FoM 1,386. Sementara struktur kristal LiBOB Hidrat juga orthorombik namun dengan nilai a, b, dan c sebesar 16,119 Å, 15,913 Å, dan 5,6182 Å dengan sudut α = β = γ = 90°, grup ruang Pbca (61), serta nilai FoM 0,824. AbstractLithium Bis ( Oxalato ) Borate(LiBOB) as lithium salt that is currently being developed as an alternativeelectrolytes for Li - Ion battery. LiBOB electrolyte is considered more environmentally friendly, LiBOB alsohave a fairly high heat stability which is equal to 302 ºC.This research aims to synthesize LiBOB thentodetermine the crystal structure and the optimum duration of sintering.At present work, the synthesis ofLithium Bisoxalato Borate (LiBOB) was done by solid-state reaction method. The raw materials was mixedhomogeneously. These samples were calcinated at 120 ºC for about 2 hours then sintered at 240 ºC withvarious durations (2, 3, and 4 hours). XRD characterization was done for identifying phases. From XRDinterpretation, there are LiBOB Hydrate and other impurities at two-hour sintered sample. There are LiBOBHydrate and H3BO3 at three-our sintered sample. There are LiBOB, LiBOB Hydrate, and other impurities atfour-hour sintered sample. The sample with 240 ºC/4 hour parameter is the most optimum sample based onthe convergention to the LiBOB and LiBOB Hydrate phases at standard commercial LiBOB sample (SigmaAldric). The crystal system of the LiBOB phase is orthorombic with lattice parameters a = 5.74 Å, b = 6.79Å, c = 14.45 Å, α = β = γ = 90º, space groupPnma (62), and FoM 1.386. On the other hand, the crystal systemof LiBOB Hydrate phase is also orthorombic with lattice parameters a = 16.119 Å, b = 15.913 Å, c = 5.6182Å, α = β = γ = 90º, space group Pbca (61), and FoM 0.824.