Amorphous interlayers between crystalline grains in ferromagnetic ZnO films

The nanograined thin films of undoped ZnO were synthesized by the wet chemistry method. Films consist of the equiaxial nanograins, and possess ferromagnetic properties. Structural investigations by the XRD and HREM reveal that the crystalline wurtzite grains do not contact each other and are completely surrounded by a layer of amorphous phase. It forms a kind of continuous foam-like network, where the amorphous intergranular phase amount could be increased by the synthesis parameters. Simultaneously, the saturation magnetization increases as well.

► Nanograined undoped ZnO films possess ferromagnetic properties.
► Crystalline wurtzite grains are completely surrounded by a layer of amorphous phase.
► The amount of amorphous intergranular phase controls the saturation magnetization.
► The amount of amorphous intergranular phase could be tailored.