Hasil Pencarian  ::  Simpan CSV :: Kembali

"La2Ti2O7 merupakan material ferroelektrik yang memiliki temperatur Curie yang tinggi, sehingga dapat digunakan sebagai sensor yang digunakan pada temperatur tinggi. Beberapa penelitian telah dilakukan untuk mendapatkan sifat material yang optimal, dengan cara subtitusi Ce, Ta, Bi kedalam material La2Ti2O7, dimana subtitusi Bi dapat meningkatkan dielektrik material. Pada penelitian ini, material La2-xBixTi2O7 dengan x = 0.1 dan 0.2 telah berhasil disintesis dengan menggunakan metode Sol-gel. Proses sintesis material menghasilkan pellet (bulk). Uji karakterisasi yang telah dilakukan pada material bulk tersebut adalah, XRD, SEM, EDX, dan Impedansi Spektroskopi. Hasil uji karakterisasi XRD, menunjukan sampel single phase, dengan struktur monoklinik dan space group P21. Hasil uji SEM dan EDX, menunjukan adanya puncak dari semua elemen prekursor dan juga ukuran rata rata grain dari sampel menurun dengan penambahan jumlah Bi. Selain itu, hasil SEM juga menunjukan bahwa ukuran dan distribusi dari morfologi kedua sampel tidak merata. Karakterisasi sifat listrik dilakukan pada rentang frekuensi 500 Hz hingga 1 MHz, dan dengan rentang temperatur 75˚C hingga 175˚C. Hasil Impedansi spektroskopi menunjukan diameter semisirkular yang semakin menurun seiring meningkatnya temperatur. Hal tersebut mengindikasikan bahwa kedua material memiliki trend sifat semikonduktor. Dielektrik material juga meningkat seiring meningkatnya subtitusi Bi. Hal tersebut disebabkan karena tinggi nya polarisasi ion Bi3+ dengan pasangan elektron bebas. Selain itu, konduktivitas dc juga meningkat seiring meningkatnya jumlah subtitusi Bi.

---

La2Ti2O7 is a ferroelectric material that has a high Curie temperature, so it can be used as a sensor that is used at high temperatures. Several studies have been carried out to obtain optimal material properties, by substituting Ce, Ta, Bi into La2Ti2O7 material, where Bi substitution can increase the dielectric. In this research, La2-xBixTi2O7 material with x = 0.1 and 0.2 has been successfully synthesized using the sol-gel method. The material synthesis process produces pellet (bulk). Characterization have been carried out on these bulk materials are XRD, SEM, EDX, and Impedance Spectroscopy. The results of the XRD characterization shows a single phase, with a monoclinic structure and space group P 1 21 1. The results of the SEM and EDX show that there were peaks of all precursor elements and also that the average grain size of the sample decreased with increasing the amount of Bi. In addition, the SEM results also show that the size and distribution of the morphology of the two samples is uneven. Characterization of electrical properties was carried out in the frequency range of 500 Hz to 1 MHz, and with a temperature range of 75˚C to 175˚C. The results of impedance spectroscopy show that the semicircular diameter decreases with increasing temperature. This indicates that the two materials have a trend of semiconductor properties. The dielectric of the material also increases with increasing Bi substitution. This is due to the high polarization of the Bi3+ ion with a lone pair of electrons. In addition, the dc conductivity also increases with increasing number of Bi substitutions."

"Providing a comprehensive and invaluable overview of the basics of crystallographic textures and their industrial applications, this book covers a broad range of both structural and functional materials. It introduces the existing methods of representation in an accessible manner and presents a thorough overview of existing knowledge on texture of metallic materials. Texture analysis has widespread use in many industries, and provides crucial input towards the development of new materials and products. There has been rapid growth in the science and art of texture analysis in the last few decades. Other topics addressed within this book include recent research on texture in thin films and non-metals, and the dependence of material properties on texture, and texture control in some engineering materials. This book constitutes an invaluable reference text for researchers and professionals working on texture analysis in metallurgy, materials science and engineering, physics and geology. By using content selectively, it is also highly accessible to undergraduate students."

"Pb doped ZnO disintesis dengan metode kopresipitasi menggunakan prekursor ZnSO4.7H2O dan PbCl2 dengan variasi konsentrasi dopant Pb (0.5%, 3%, 3.5% dan 5%) pada kondisi pH 13 serta temperatur pengeringan 100 0C selama empat jam. Sampel dikarakterisasi dengan X-Ray Diffraction (XRD) dan Energy Dispersive X-Ray (EDX) untuk melihat morfologi serta komposisi Pb doped ZnO. Hasil karakterisasi XRD menunjukkan terbentuknya fase utama wurtzite ZnO serta ditemukan fase sekunder PbO. Analisa lebih lanjut menunjukkan perubahan parameter kisi wurtzite ZnO (a=3.252, c=5.216) serta penurunan ukuran kristal (18 hingga 12 nm) dengan penambahan dopant Pb. Sifat optik Pb doped ZnO dikarakterisasi menggunakan UV-Vis Spectroscopy dan diperoleh penurunan energi celah pita ZnO (3.379 hingga 3.310 eV). Penurunan energi celah pita ZnO mengindikasikan terbentuknya pita tambahan di bawah pita konduksi ketika terjadi substitusi Pb ke dalam matriks ZnO. Kemampuan fotokatalis Pb doped ZnO dikarakterisasi dengan metode Photocatalytic Activity (PCA) menggunakan sinar UV pada rentang 200–800 nm selama 1 jam dan didapatkan efisiensi fotokatalis terbaik pada sampel Pb doped ZnO dengan kadar dopant 3.5%.

---

Pb doped ZnO were synthesized by coprecipitation with ZnSO4.7H2O and PbCl2 (0.5%, 3%, 3.5% and 5%) at pH 13 and 100 0C for four hours. Morphology and composition of Pb doped ZnO were characterized by X-Ray Diffraction (XRD) and Energy dispersive X-ray (EDX). XRD spectrum indicated the formation of wurtzite ZnO and PbO. Further analysis showed that lattice parameter of ZnO has changed (a = 3.252, c = 5.216) and crystallite size has decreased (18 to 12 nm) with the addition of Pb. The optical properties of Pb doped ZnO were characterized using UV-Vis spectroscopy and showed that bandgap energy was decreased (3.379 to 3.310 eV). This indicated the formation of additional bandgap below the conduction band when the substitution of Pb into the ZnO matrix. Photocatalytic Activity (PCA) of Pb doped ZnO photocatalysts were characterized using UV in 200-800 nm for 1 hour and Pb Doped ZnO 3.5% has the best photocatalytic activity.

"