Terbium, classified as a heavy rare earth element (HREE), exhibits malleable and ductile characteristics. It does not occur naturally as a simple substance but is present in multiple minerals, including cerite, gadolinite, monazite, xenotime, and euxenite. The majority of global terbium mining takes place in China or Myanmar, while refinement is predominantly handled in China. While the Nd2Fe14B phase delivers exceptional energy product, remanence, and coercivity, its performance drops markedly with rising temperatures, rrendering it inappropriate for applications where temperatures are elevated.
Nevertheless, these thermal characteristics can be improved by substituting a small percentage of neodymium with either Dysprosium or Terbium. Terbium outperforms Dysprosium in effectiveness for this purpose, though its higher cost stems from scarcer natural occurrence.Terbium is generally utilized for manufacturing of double-high Neodymium magnets (high coercivity and high energy product). The fluctuations in Terbium metal prices notably affect the cost trends of high-coercivity Neodymium magnets, in addition to those of PrNd mischmetal. To optimize rare earth resource utilization, bolster supply chain reliability, and secure economic benefits, magnet manufacturers and end-users alike are actively seeking ways to minimize or eliminate reliance on heavy rare earths such as Dysprosium and Terbium, resulting in the development of various HREE-less or HREE-free solutions, with grain boundary diffusion (GBD) technology standing out prominently.
