Innovative Approaches about Lead Free Electroceramics

Innovative Approaches about Lead Free Electroceramics

Electro ceramics play an important role in military, health, automotive, air and space and most of daily technologies. The material properties that provide mechanical/electrical energy conversion, enable these materials to be used in many advanced technology areas. Electro ceramics are used in the James Webb space telescope, which provides the images that we will solve the mystery of the galaxies, or in an ultrasound device that gives detailed information about whether our child is healthy or not. Today, sensors, actuators and transducers are basic components for smart automation systems in the fourth industrial revolution (IR4). It is also predicted that there will be a significant increase in the need for similar advanced ferroelectric systems in many treatment - diagnostic methods and robotic surgeries etc.

All of these applications have their unique performance requirements such as high mechanical coupling factor, high Curie temperature, high piezoelectric coefficient, low dielectric loss etc. The expected electrical performances for each application may vary, and today compositions that meet these performances are mostly lead based ones. Considering hazardous lead based piezo ceramics globally, there are consumptions of 500k tons/year. These amounts are unacceptable in terms of sustainability of the world. Even thinking that so much lead is handled in factories, dusting to atmosphere and contamination of water sources during raw material preparation processes, and that some of it is released into the atmosphere by evaporation during the sintering processes creates a driving force for our consciences as much as RoHS directives.

 At this point, it is important not only to develop lead-free electro ceramics with desired electrical performances in the laboratory environment, but also to make feasible the production technologies that will ensure their widespread use. Crystal structure engineering and microstructure engineering are two available pathways for developing high performance lead free electro ceramics to replace lead based ones. By producing textured ceramics (microstructure engineering), the electrical performances can be increased to approach the single crystal performances. This means that the performances of lead-free compositions can approach those of leaded ones. The template particles are one of the most important components in the production of textured ceramics.

With the titanate and niobate-based templates developed by Entekno, it is possible to texture KNN, NBT and BT based lead-free electro ceramics.

Dr. Murat AVCI

Electroceramics R&D Manager