Russian scientists achieve record-precision molecular thermometer

Russian researchers have developed luminescent materials that help measure the temperature of microscopic objects – such as individual cells or overheating microchips – without direct contact.

The scientists created two new compounds containing rare-earth metal ions, europium and terbium. These materials operate across a wide temperature range – from –196 °C to +126 °C – making them suitable as precise molecular thermometers. This was reported on the website of the Russian Science Foundation.

The method is based on luminescent thermometry – a technique for determining temperature according to the emission characteristics of a substance. The colour and intensity of the emission change depending on temperature, enabling highly accurate measurements.

The researchers synthesised luminescent complexes incorporating europium and terbium ions. The metals were bonded with organic groups in the form of multiple carbon rings. It is noted that the complexes consisted of the same atoms, but their mutual arrangement differed slightly. Comparison of the materials showed that altering the position of even a single atom in the molecule increases temperature sensitivity by 40 per cent.

For comparison with existing analogues, the scientists used the parameter of integral sensitivity, which considers not only maximum accuracy but also operational stability across the entire temperature range. By this measure, one of the new materials outperformed existing molecular thermometers. The development may find applications in medicine and microelectronics, where monitoring temperature at the micro level is critical.