Optical Characteristics of Nano-forsterite Powders with Natural Silica Sand as Si Source
Upik Nurbaiti (a*), Wasi Sakti Wiwit Prayitno (a), Khumaedi (a), Suminar Pratapa (b)
a) Physics Department, Universitas Negri Semarang, Jl. Raya Sekaran Gunungpati, Semarang 50221, Indonesia
*upik_nurbaiti[at]mail.unnes.ac.id
b) Physics Department, Institut Teknologi Sepuluh Nopember Surabaya, Jl. Arief Rahman Hakim, Surabaya 60111, Indonesia
Abstract
Nano forsterite powders have been successfully synthesized via ultrasonic assistant for the starting materials and followed by solid reaction and calcination steps. The synthesis products were greenish powders with forsterite as the dominating phase as revealed by XRD data analysis. The formation of forsterite was also confirmed by FTIR spectrometry and supported by SEM images. The phase composition after calcination at 950 °C for 4h was 93.9wt% forsterite and 6.1wt% periclase. The forsterite crystal was nanometric according to the XRD data, while the density of the powder was 2.88g/cm3. UV-Vis spectrum of the powder showed relatively strong absorption peaks particularly at 635, 660, 670, 680, 695 and 705 nm which can be associated with the greenish color of the product and is different from previous studies. Therefore, it can be concluded that high purity greenish forsterite can be formed at 950 °C calcination temperature as previously reported, except that the raw materials were subjected to ultrasonic treatment.
Keywords: nano-forsterite; optical characteristics; silica sand; ultrasonic treatment
Topic: Synthesis and Characterization Techniques