Substitutes

Substitutes and Alternatives for Terbium

The availability of viable substitutes is a key factor in assessing Terbium's criticality. Across its 3 primary applications, substitution options range from commercially viable alternatives with performance trade-offs to applications where Terbium currently has no effective substitute.

Substitution Analysis by Application

The following table details available substitutes for Terbium across its primary applications, including the trade-offs involved:

Performance Trade-offs

In most applications, substituting Terbium involves measurable performance penalties. Terbium and dysprosium serve the same function in NdFeB magnets (improving high-temperature coercivity); terbium is more effective per atom but rarer and more expensive; dysprosium is the preferred additive by volume. In high-performance applications such as permanent magnets (ndfeb additive), these trade-offs can be particularly significant.

Research and Development

Active research programs are underway to develop improved substitutes and to reduce the amount of Terbium required per unit of product (thrifting). However, timelines for commercializing new alternatives typically span years to decades. The limited substitutability of Terbium is a primary driver of its high criticality rating, prompting government-funded substitution research programs.