Extraction and characterization of mixed phase KNO 2 -KNO 3 nanocrystals derived from flat-leaf green spinach

ISSN： 1402-4896

Source： Physica Scripta, Vol.87, Iss.1, 2013-01, pp. : 15603-15607

Disclaimer: Any content in publications that violate the sovereignty, the constitution or regulations of the PRC is not accepted or approved by CNPIEC.

Previous Menu Next

Abstract

Naturally available green spinach, which is a rich source of potassium, was used as the key ingredient to extract mixed-phase ferroelectric crystals of nitrite and nitrate derivatives (KNO₂ + KNO₃). The KNO₃ phase was found to be dominant for higher pH values, as revealed by the x-ray diffraction patterns. The characteristic optical absorption spectra exhibited intra-band π-π* electronic transitions, whereas Fourier transform infrared spectra exhibited characteristic N-O stretching vibrations. Differential scanning calorimetry revealed a broad endothermic peak at ∼121.8 °C, highlighting a transition from phase II to I via phase III of KNO₃. Obtaining nanoscale ferroelectrics via the adoption of green synthesis is economically viable for large-scale production and possible application in ferroelectric elements/devices.