Fig. 2: Evolution of color changes of nitrogen doped lutetium hydrides with varying pressures.
From: Observation of non-superconducting phase changes in nitrogen doped lutetium hydrides
a Optical images of pressure-induced color changes of the produced LuH2±xNy samples during compression (upper images) and decompression (down images) processes in a DAC chamber with silicon oil as pressure medium. b Phase diagram of phase I (blue), phase II (purple), phase III (pink) and phase IV (red) of the LuH2±xNy samples in different pressure media. Two runs were carried out in silicon oil medium with Re-gasket thickness of 32 μm and 44 μm, respectively. The sample chamber with thick gasket underwent expansion, creating shear stresses, which helped reduce the critical pressures of color changes in the LuH2±xNy sample (Supplementary Fig. 10). c Optical images of the samples showcasing reduced critical pressures of the LuH2±xNy samples mixed with nanodiamonds by internal stress in the NaCl pressure medium.
