Providing answers about nano relaxors.

• Position: Heart Implants

Important information about the nanoscale properties of materials called relaxors, which can be used in electronic devices to change temperature or shape, has been determined by physicists at the University of Arkansas, Fayetteville. The discoveries could help maximize the efficient use of relaxors to create better medical ultrasound sensors and heart implants.

You can find the materials known as relaxors in many everyday appliances, in life-saving heart implants, and in most sensors but, despite their wide use, "we still didn't have a realistic theory of how these things work," admits Sergey Prosandeev, professor in the Department of Physics.

Transitions in the polarity of relaxors seem disorderly, which would make them difficult to control. However, Prosandeev and his colleagues wondered if order might lie beneath the disorder. The researchers performed calculations on a certain type of relaxor, barium zirconium titanium oxide, Ba(Zr,Ti)O3. They found that the relaxor stopped being polarized at higher temperatures.

Meanwhile, the material developed nanoregions with the same polarities at lower temperatures. The researchers also showed that this occurs because of competition between opposite effects, such as differences in the way titanium ions and zirconium ions want to move or stay in...