Electrical Characteristics of NTC Thermistor Ceramics Made of Mechanically Activated Fe{sub 2}O{sub 3} Powder Derived from Yarosite

Journal Article · Mon Mar 17 04:00:00 EDT 2008 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.2906043· OSTI ID:21136840

Syarif, D Gustaman ^[1]; Ramelan, A ^[2]

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1. Nuclear Technology Center for Materials and Radiometry-BATAN, Jl. Tamansari 71, Bandung, 40132 (Indonesia)
2. Material Study Program, ITB, Jl. Ganesha 10, Bandung (Indonesia)

Electrical characteristics of ceramics for NTC thermistor made of mechanically activated Fe{sub 2}O{sub 3} powder which was derived from yarosite mineral has been studied. The powder of Fe{sub 2}O{sub 3} was derived from yarosite mineral by precipitation and calcination. The powder was mechanically activated by blending using an electric blending machine. The ceramics were produced by pressing the calcined and activated powders to produce pellets and sintering the pellets at 1100 deg. C and 1200 deg. C for 1 hour in air. Electrical characterization was done by measuring electrical resistivity of the ceramics at various temperatures (25 deg. C-100 deg. C). Microstructure and structural analyses were carried out by using a Scanning Electron Microscope (SEM) and X-ray diffraction (XRD), respectively. The XRD analyses showed that the sintered ceramics had crystal structure of hexagonal (hematite). The presence of second phase could not be identified from the XRD analyses. From SEM data, it was known that the ceramics from activated powder had larger grains due to small size of the activated powder. According to the electrical data, it was known that the ceramics made of the activated powder had lower thermistor constant (B) and room temperature electrical resistivity ({rho}{sub RT}). The value of B and {rho}{sub RT} of the produced ceramics fitted market requirement.

• OSTI ID: 21136840
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 989; ISSN APCPCS; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CALCINATION
CERAMICS
CRYSTAL STRUCTURE
ELECTRIC CONDUCTIVITY
HEMATITE
IRON OXIDES
MICROSTRUCTURE
PRESSING
SCANNING ELECTRON MICROSCOPY
SINTERING
TEMPERATURE DEPENDENCE
THERMISTORS
X-RAY DIFFRACTION