Gadolinium is a chemical element with symbol Gd and atomic number 64. It is a silvery-white, malleable and ductile rare-earth metal. It is found in nature only in combined (salt) form.
Three reasons Gadolinium stands out
- 1
Used in MRI contrast agents and nuclear reactors.
- 2
It has the highest neutron-absorption cross-section of any stable element, making it extremely useful in reactor control.
- 3
It is strongly attracted to magnets at room temperature, an unusual property for a non-iron-group metal.
Magnetism near room temperature
Gadolinium changes its magnetic behavior near ordinary room temperature, making it a favorite demonstration of magnetic phase transitions. In MRI contrast agents, gadolinium ions are locked inside chelating molecules because the free ion is toxic. The metal also has an enormous appetite for neutrons.