High-Sensitivity Single Crystal Silicon Pressure Scale for High-Pressure and High-Temperature Diamond Anvil Cell Experiments

Accurate pressure calibration is critical for high-pressure and high-temperature experiments in diamond anvil cells. While cubic boron nitride (c-BN) is a common standard, its precision is often compromised at low pressures by broad and fluctuating Raman peaks. Here, we establish single-crystal silicon (SC-silicon) as a superior Raman-based pressure calibrator within the range of 0–10 GPa and 300–800 K. Systematic comparative measurements reveal that SC-silicon outperforms c-BN, featuring higher pressure sensitivity (∼4.65 vs ∼3.2 cm–1/GPa), significantly narrower and more stable full width at half-maximum, and stronger signal intensity. Based on these data, we propose a high-precision empirical P–T calibration equation and advocate for a complementary dual validation strategy. To validate this scale, we revisited the phase diagram of manganotantalite. The results refine the phase transition pressure at 600 K from ∼14.2 to ∼12.7 GPa, yielding a more accurate Clapeyron slope. This work establishes SC-silicon as a reliable, high-sensitivity tool and a multifunctional calibrant for investigating inorganic solids under extreme conditions.