A COMPREHENSIVE STUDY ON THE MICROSTRUCTURE AND OPTICAL PROPERTIES OF Fe3O4 NANOPARTICLES BY VARIATION OF TEMPERATURE AND NaOH CONCENTRATION

This work was aimed at optimizing the microstructure and optical properties of Fe3O4 by variation of synthesis temperature and NaOH concentration. The nanoparticles have been synthesized from iron sand by using the coprecipitation method. The temperature was varied of 60oC, 80oC, and 100oC, while NaOH concentration was 3 molar, 5 molar, and 7 molars. The microstructural parameters were characterized by using X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) techniques. The optical properties were characterized by using Fourier Transform Infrared Spectroscopy (FTIR) and UV-Vis Spectroscopy, consecutively. The results showed that the crystallite size of Fe3O4 increase with an increase of synthesis temperature due to higher thermal energy driving the nucleation process. The crystallite sizes are in the range of 3.77 nm – 20.37 nm. Increasing NaOH concentration also affected the increase in crystallite sizes. On the other hand, an excess of NaOH concentration influences the formation of smaller crystallite sizes of Fe3O4 with smaller crystal density and larger microstrain. The existence of Fe2+-O and Fe3+-O vibration in FTIR spectra confirmed the formation of Fe3O4 nanoparticles. The direct and indirect optical gap energies of Fe3O4 were in the range of 3.15 eV – 3.39 eV and 2.39 eV – 2.91eV. The synthesis temperature and NaOH concentration have a significant role in controlling the properties of Fe3O4. &nbsp

Synthesis and Characterization of the Microstructure and Functional Group Bond of Fe3o4 Nanoparticles from Natural Iron Sand in Tobelo North Halmahera

The Fe3O4 nanoparticles have been successfully synthesized from natural iron sand by using co-precipitation method at a temperature of 56oC. The elemental identification, structural characterization, and bonding analysis were carried out using XRF, XRD, and FTIR, respectively. The sample nanoparticles contain elements of Al, P, Ca, Ti, V, Cr, Mn, Ni, Cu, Zn, Rb, Re, Bi, and Fe. The composition of Fe element is 87.37%. The sample of the nanoparticle exhibited as the Fe3O4 which was shown by the diffraction pattern that belongs to a cubic spinel structure of Fe3O4. The crystallite size of the nanoparticle is 42.25 ± 0.42 nm. The lattice parameter was found at 8.384 ± 0.049 Å. The crystallite density is 5.232 103 kg/m3 while the lattice strain is 1.413 10-3/line. The FTIR spectra confirm that the existence of Fe-O stretching vibration in the range frequency of 658 cm-1-506 cm-

Investigation of The Distribution and Fe Content of Iron Sand at Wari Ino Beach Tobelo Using Resistivity Method with Werner-Schlumberger Configuration

This research aimed to investigate the distribution, volume, and concentration of iron sand at Wari Ino Beach Tobelo. The resistivity method with Werner-Schlumberger configuration was applied to investigate the iron sand distribution. The measurements were set-up on 3 lines that run parallel along the coast of Wari Ino Village. The length of each trajectory was 150 meters with a spacing of 10 meters for each electrode. Data acquisition was carried out by using geoelectric instruments to obtain current injection (I) and voltage (V). The analysis was carried out by using RES2DINV and ROCKWORK software to obtain 2-D and 3-D cross-section models for interpreting the distribution and volume of the iron sand. The analysis and interpretation were supported by geological data of the location. Furthermore, the Fe content was characterized by using X-Ray Fluorescence Spectroscopy (XRF). There results show that the volume of the iron sand in each trajectory was 109,355 m3; 180,254 m3; and 120,556 m3. The total volume of iron sand along the three trajectories was up to 405,335 m3. The Fe content in the form of a free element is 67.41%, 57.12%, and 73.40%. The Fe content in the form of hematite mineral (Fe2O3) was 57.92%, 45.82%, and 65.47%

Kalkulus Diferensial

Sistematika buku ini dengan judul “Kalkulus Diferensial” terdiri atas 14 bab yang dijelaskan secara rinci dalam pembahasan mengenai konsep dan Aplikasi diantaranya: Sistem Bilangan Real, Pertidaksamaan, Interval dan Nilai Mutlak, Definisi dan Pengoprasian Fungsi, Limit dan Kontinuitas Fungsi, Definisi Turunan, Teorema Turunan dan Fungsi Aljabar, Nilai Turunan Fungsi Trigonometri, Eksponensial dan Logaritma, Penerapan Aturan Rantai untuk menentukan Turunan, Turunan Tingkat Tinggi, Turunan Fungsi Implisit, Nilai Ekstrim, Kemotonan dan Kecekungan dan Persamaan Diferensial Bias

Pengantar Statistika 2

Sistematika buku ini dengan judul “Pengantar Statistika 2” terdiri atas 14 bab yang dijelaskan secara rinci dalam pembahasan mengenai konsep dan Aplikasi diantaranya: Pengujian Hipotesis. Uji Kuadrat dan Analisis Variansi, Analisis Regresi, Analisis Multiple, Analisis Kolerasi Sederhana, Analisis Korelasi Multiple, Analisis Uji Anova 1 Arah, Wilcoxon, Mann-Withney, Korelasi Non Parametik, Kruskal Walls, Linear Diskriminant Analisis, Quadratic Discriminant Analysis dan Corelasi Canonical