(a) EMT derived real parts of uniaxial permittivity components of Sb₂S₃-TiN HMM when Sb₂S₃ is in the amorphous and crystalline phases. (b) Excited BPP mode of Sb₂S₃-TiN HMM for both phases of Sb₂S₃. (c) Calculated phase difference between TM and TE polarization for both phases of Sb₂S₃. (d) Calculated tunable GH shift of the HMM. (e) Real time tunable refractive index sensing by injecting different weight percentage concentrations of glycerol in distilled water.