It Takes Indium to Make the Perfect Blue

10. August 2021 | Knowledge

Indium and manganese make colors shine. The discovery came about by accident.

Research and development in new materials don’t always go to plan. In 2009, the Ph.D. student Andrew Smith and Professor Mas Subramanian from Oregon State University were actually in search of new materials for electrical components. In the course of their quest, they heated a mix of yttrium, indium and manganese (YIn1-xMnxO3) to 1,200 °C in a furnace. The result was a new compound displaying a brilliant blue but of little use for the intended purpose.

And another coincidence

Subramanian, who had previously worked for the chemical corporation Dupont, recognized the potential of the compound as the basis for a new color pigment. Blue pigments have been in use for many thousands of years but often contain toxic components. Furthermore, over a number of years, they tend to lose their brilliance. YInMn Blue, Oregon Blue or Mas Blue, as the new dye is called, is a completely different story. This is chemically stable, heat reflecting and UV absorbing. The color intensity can be varied by adjusting the ratio of indium to manganese.

The new color has been available for sale since 2016. According to Professor Subramanian, it is suitable, among other uses, for restoring works of art. And junior artists too are benefiting from the discovery. Under the melodious name Bluetiful, the color is now also available as a wax crayon.

Following the discovery, the team working with Subramanian developed further pigments based on YIn1-xMnxO3 by adding copper or iron. The new challenge is the quest of a brilliant, stable and heat-reflecting red. According to researchers, this is the most difficult color to produce synthetically.

Photo: Oregon State University

California MP_Materials