Slovenian researchers make breakthrough in materials science

The group of 11 researchers, including one from Japan and one from Switzerland, was the first to prove the accumulation of charged defects at domain walls in bismuth ferrite.

They thus explained the mechanism of local electrical conductivity in the material, which theories have been announcing since 2009.

The group further showed "that the local domain-wall conductivity can be tailored by controlling the atmosphere during high-temperature annealing".

"This work has possible implications for engineering local conductivity in ferroelectrics and for devices based on domain walls," reads the abstract of the research published in the acclaimed Nature Materials magazine.

According to the authors, bismuth ferrite is a promising material that could be used in manufacturing sensors and actuators meant for working in high-temperature environment.

Similar materials are currently used in ultrasonic devices, but their use is limited by temperature.

"In the event we want to use ultrasound in an environment such as gas turbines or nuclear power stations, where temperatures typically rise over 200 degrees Celsius, the materials in use today are mostly unsuitable."

The Slovenian-led team, Tadej Rojac, Andreja Benčan, Goran Dražić, Naonori Sakamoto, Hana Uršič, Boštjan Jančar, Gašper Tavčar, Maja Makarovič, Julian Walker, Barbara Malič and Dragan Damjanović, explained that the discovery could have applicable consequences in the long run.

"In principle, if we require conductivity, it can be increased, and if we don't, we can prevent it. New discoveries will create the path for the transfer of the material to the industry in the form of various commercially interesting high-tech products."

The authors wanted to publish the research in November last year, but needed an extra year to carry out additional experiments to convince the reviewers of the validity of the conductivity model.