One expects a single crystal to be precisely what its name implies: a periodic array of atoms, in which each unit cell is identical to any other. But in certain oxides of manganese, a spectacularly diverse range of exotic electronic and magnetic phases can coexist at different locations within a single crystal. This striking behavior arises in manganites because their magnetic, electronic, and crystal structures interact strongly with one another. For example, a ferromagnetic metal can coexist with an insulator in which the electrons and their spins adopt intricate patterns.
The complexity of such phases, and the apparent near balance between them, comes as a surprise. In systems with multiple phases, one expects any given set of external conditions to overwhelmingly favor one phase over all others. But in chemically homogeneous manganites it turns out to be surprisingly easy to achieve phase coexistence using a wide range of tuning parameters....
