The Semi-Cone Angles in Conical Tb-Er and Dy-Er Alloys

The semi-cone angles of Tb and Er in Tb-Er alloys and of Dy and Er in Dy-Er alloys both in conical structure are calculated by analyzing the results of our spin echo measurements on these alloys. It was found that the angles of individual components are different with each other, indicating a double cone structure. A simple molecular field calculation shows that really such double cone structure is the most stable one in these alloys, provided that the exchange and anisotropy constants are properly chosen.