Low Power Resistive Oxygen Sensor Based on Sonochemical SrTi0.6Fe0.4O2.8 (STFO40)

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Engineering

Background:

• Development of advanced materials for gas sensing applications is crucial.
• Strontium titanate ferrites (STFO) are promising candidates for oxygen sensors.
• Existing STFO powders may have limitations in specific applications.

Purpose of the Study:

• To report a sonochemical synthesis method for nanostructured SrTi0.6Fe0.4O2.8 (Sono-STFO40) powder.
• To evaluate the performance of oxygen sensors fabricated using Sono-STFO40.
• To compare Sono-STFO40 with a commercial STFO powder (STFO60).

Main Methods:

• Sonochemical synthesis of nanostructured STFO powder.
• Characterization using X-ray diffraction (XRD), Mössbauer spectroscopy, and Scanning Electron Microscopy (SEM).
• Fabrication of resistive oxygen sensors on Silicon-on-Insulator (SOI) micro-hotplates using dip-pen nanolithography (DPN).

Main Results:

• Sono-STFO40 powder exhibited a typical grain size of 50 nm.
• Oxygen sensors based on Sono-STFO40 showed good sensitivity and fast response (25 s).
• The Sono-STFO40 sensor demonstrated low power consumption (80 mW) at 650 °C.

Conclusions:

• Sonochemical synthesis is an effective method for producing nanostructured STFO for oxygen sensors.
• Sono-STFO40 based sensors perform comparably to STFO60 sensors.
• Sono-STFO40 is a suitable material for oxygen detection in demanding environments.