Because the fraction of events that occur without phonon emission or absorption increases greatly at low temperatures, spectroscopy utilizing this effect is usually done at the temperature of liquid helium. Pound and Rebka used it to verify the existence of gravitational redshift, and its namesake first observed it in iridium atoms. Resulting in the emission of gamma rays with a small energy spread, FTP, identify this eponymous effect in which lattice atom emits a photon, but the lattice itself 
Because the fraction of events that occur without phonon emission or absorption increases greatly at low temperatures, spectroscopy utilizing this effect is usually done at the temperature of liquid helium. Pound and Rebka used it to verify the existence of gravitational redshift, and its namesake first observed it in iridium atoms. Resulting in the emission of gamma rays with a small energy spread, FTP, identify this eponymous effect in which lattice atom emits a photon, but the lattice itself absorbs the recoil.
Because the fraction of events that occur without phonon emission or absorption increases greatly at low temperatures, spectroscopy utilizing this effect is usually done at the temperature of liquid helium.
{Mossbauer} effect