In a ferromagnetic material, atoms spontaneously align over a macroscopic volume called a:

1. Individual atoms in a ferromagnet already carry dipole moments. 2. What distinguishes a ferromagnet is that neighbours cooperate. 3. They spontaneously align themselves in a common direction over a macroscopic volume called a domain. 4. So the answer is a domain. _Source: syllabus Physics Part I, Ch 5 'Magnetism and Matter'_