Investigating the Potential of Cr³⁺-Doped Pyroxene for Highly Sensitive Optical Pressure Sensing

Abstract

Luminescent manometry has gained significant popularity in recent years due to its capability to provide in situ pressure measurements in a remote manner. Therefore, there is a growing need to identify phosphors with pressuredependent spectroscopic properties that can be utilized to develop highly sensitive pressure sensors operating over a wide pressure range. Hence, we present a novel temperature-invariant luminescent manometer based on Cr 3+ ion emission in pyroxene Ca 0.8 Sr 0.2 MgSi 2 O 6 :Cr 3+ . We utilized two readout modes, including an innovative luminescent pressure sensing ratiometric approach based on the broad emission band associated with the 4 T 2g → 4 A 2g electronic transition of Cr 3+ ions. This approach provided an exceptionally high sensitivity of S R = 50.7 ± 0.5% GPa −1 and ensured temperature-independent pressure measurements, thus offering highly reliable readouts. Furthermore, the proposed readout mode, which leverages changes in luminescence kinetics, demonstrated high sensitivity at high pressure at around 5 GPa (S R ∼ 8 ± 0.2% GPa −1 ) surpassing the performance of luminescence kinetics-based manometers reported to date. Consequently, Ca 0.8 Sr 0.2 MgSi 2 O 6 :Cr 3+ emerges as a highly promising phosphor with significant application potential for pressure sensing across a broad pressure range.