Abstract
A one-pot polymerization method using citric acid and glucose for the synthesis of nano-crystalline BaFe0.5Nb0.5O3 is described. Phase evolution and the development of the crystallite size during decomposition of the (Ba,Fe,Nb)-gel were examined up to 1100 °C. Calcination at 850 °C of the gel leads to a phase-pure nano-crystalline BaFe0.5Nb0.5O3 powder with a crystallite size of 28 nm. The shrinkage of compacted powders starts at 900 °C. Dense ceramic bodies (relative density 90 %) can be obtained either after conventional sintering above 1250 °C for 1 h or after two-step sintering at 1200 °C. Depending on the sintering regime the ceramics have average grain sizes between 0.3 μm and 52 μm. The optical band gap of the nano-sized powder is 2.75(4) eV and decreases to 2.59(2) eV after sintering. Magnetic measurements of ceramics reveal a Néel temperature of about 23 K. A weak spontaneous magnetization might be due to the presence of a secondary phase not detectable by XRD. Dielectric measurements show that the permittivity values increase with decreasing frequency and rising temperature. The highest permittivity values of 10.6104 (RT, 1 kHz) were reached after sintering at 1350 °C for 1 h. Tan values of all samples show a maximum at 1 2 MHz at RT. The frequency dependence of the impedance can be well described using a single RC-circuit.
Koferstein, R. (2021). Magnetic, Optical, Dielectric, and Sintering Properties of Nano-crystalline BaFe0.5Nb0.5O3 Synthesized by a Polymerization Method. Afribary. Retrieved from https://afribary.com/works/magnetic-optical-dielectric-and-sintering-properties-of-nano-crystalline-bafe0-5nb0-5o3-synthesized-by-a-polymerization-method
Koferstein, Roberto "Magnetic, Optical, Dielectric, and Sintering Properties of Nano-crystalline BaFe0.5Nb0.5O3 Synthesized by a Polymerization Method" Afribary. Afribary, 02 Aug. 2021, https://afribary.com/works/magnetic-optical-dielectric-and-sintering-properties-of-nano-crystalline-bafe0-5nb0-5o3-synthesized-by-a-polymerization-method. Accessed 27 Nov. 2024.
Koferstein, Roberto . "Magnetic, Optical, Dielectric, and Sintering Properties of Nano-crystalline BaFe0.5Nb0.5O3 Synthesized by a Polymerization Method". Afribary, Afribary, 02 Aug. 2021. Web. 27 Nov. 2024. < https://afribary.com/works/magnetic-optical-dielectric-and-sintering-properties-of-nano-crystalline-bafe0-5nb0-5o3-synthesized-by-a-polymerization-method >.
Koferstein, Roberto . "Magnetic, Optical, Dielectric, and Sintering Properties of Nano-crystalline BaFe0.5Nb0.5O3 Synthesized by a Polymerization Method" Afribary (2021). Accessed November 27, 2024. https://afribary.com/works/magnetic-optical-dielectric-and-sintering-properties-of-nano-crystalline-bafe0-5nb0-5o3-synthesized-by-a-polymerization-method