Anisotropic magnetic flakes

An anisotropic magnetic flake, for forming a reflective coating, comprising a two-dimensional layered structure having a thickness in a range of 50 nm to 10 microns and a longest planar dimension in a range of 1 micron to 500 microns, the two-dimensional layered structure comprising:

• a continuous magnetic layer, absent of a grating, for aligning the anisotropic magnetic flake substantially parallel to a surface of the reflective coating when the anisotropic magnetic flake is disposed in a liquid carrier and under influence of an external magnetic field,
• the continuous magnetic layer having a first surface and an opposing second surface;
• and
• a first reflector layer disposed on the first surface and a second reflector layer disposed on the second surface, such that the continuous magnetic layer is contained therebetween,
• wherein the continuous magnetic layer comprises a magnetic material having a coercivity of less than about 2000 Oe and has a structure that provides in-plane magnetic anisotropy oriented in a direction that is at an angle of at least 20 degrees relative to the longest planar dimension,
• wherein the direction of the in-plane magnetic anisotropy is substantially orthogonal to two substantially parallel sides, of the two-dimensional layered structure, for alignment of the anisotropic magnetic flake side-by-side with one or more other anisotropic magnetic flakes of a same structure, and
• wherein a gap between the anisotropic magnetic flake and an anisotropic magnetic flake, of the one or more other anisotropic magnetic flakes, is no greater than 500 nm.