Very low thermal expansion materials operative over selective temperature region by tailoring the tetragonality of PbTiO 3

The article deals with the thermal expansion properties of some diluted PbTiO${}_3$ (PT) based ceramic compounds. We have tailored the negative thermal expansion (NTE) coefficient of PT by substituting both at the Pb and Ti sites with different elements, with an intention to achieve very low thermal expansion coefficient. The choice of substitutional elements with appropriate proportions gives us materials with very low thermal expansion, operative over a wide range of temperature (from well above the room temperature to well below it). Moreover, we have shown an effective way to select the operative temperature region of their performance, even without performing the actual dilatometric experiment.