Holmium oxide, also known as holmium sesquioxide, chemical formula Ho2O3, is a compound composed of the rare earth element holmium and oxygen. It is pale yellow or yellow powder, has excellent paramagnetism and high melting point, and is one of the strongest paramagnetism known.
Holmium oxide has been widely used in many fields. In the manufacturing industry, it is used to make new light sources dysprosium-holmium lamps to improve lighting efficiency. At the same time, it is also used as an additive to yttrium iron or yttrium aluminum garnet to enhance the properties of the material. In the scientific field, holmium oxide is commonly used as a standard for spectrophotometric spectrometer calibration, and its sharp absorption peak facilitates accurate measurement.