1958

Mössbauer effect

• Gases absorb and emit X-rays,
• but not gamma rays. When gamma rays
• hit atoms of a gas, the atoms recoil
• and the energy is lost,
• so nuclear resonance can not be observed.
• Rudolf Mössbauer found
• that solid iridium behaved differently.
• Nuclear resonance can be observed
• as solids absorb most of the gamma rays
• without recoil, and fluoresce,
• nuclei delivering the energy of impacts
• to their surrounding crystal lattice.

Mössbauer spectroscopy

• Mössbauer spectroscopy observes nuclear interactions,
• which depend on small shifts of energy levels
• between particles bound into atomic nuclei.
• An isomeric shift
• occurs in an atomic spectra
• when one nuclear isomer replaces another.
• A chemical shift
• is a shift in resonance energy of a nucleus
• when electrons shift in their orbitals.
• A quadrupole split
• occurs in the Mössbauer spectrum
• when the spin quantum number is greater than one half.
• A hyperfine-structure split
• occurs in the Mössbauer spectrum
• when nuclear multipole moments intereact with internally generated fields.
• A Zeeman split
• occurs in an atomic spectrum
• when exposed to a magnetic field.
• Mössbauer spectroscopy helps determine
• relative concentrations of chemicals in a solid
• and can help show the crystalline size and grain structure of a material.

Non-invasive diagnosis

• Geologists and planetary landers
• on Earth, moon, and Mars
• probe meteors and other rocks
• Oil companies set explosives
• and analyze seismic waves
• to find oil and gas reservoirs.
• Sonograms of expectant mothers determines gender.
• Echocardiograms determine heart irregularities.
• Home monitors show blood pressure.
• My doctor taps my back
• while listening with a stethoscope
• to evaluate lung functionality.