Terbium

Heavy rare earth used in green phosphors, solid-state devices, and high-performance magnetostrictive alloys (Terfenol-D).

Properties

Atomic Mass

158.93

Density

8.23 g/cm³

Melting Point

1356°C

Boiling Point

3230°C

Discovered

1843 by Carl Gustaf Mosander

Terbium (Tb): The Powerful Yellow‑Green

Named after the Swedish village of Ytterby, Terbium was isolated in 1843 by Carl Gustaf Mosander. It is renowned for highly efficient green phosphors that light up displays and lighting. Its most strategic application is in magnetostriction: with dysprosium (Terfenol‑D), it expands or contracts strongly under a magnetic field—indispensable for high‑performance acoustic transducers and advanced precision sensors.

Key Applications

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Green phosphors (displays, lighting)

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Magnetostrictive actuators (Terfenol-D)

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Fuel cells and solid-state devices

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High-efficiency LEDs

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Magneto‑optical isolators and storage

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High‑contrast LCD backlighting phosphors

Market Data

Primary Supply

China over 85%; limited elsewhere

Demand Trend

Robust specialized growth at 5.8% CAGR, increasing in sensors, magnets, and wind/EV tech; aligned with clean energy demands

Reserves

Limited, small share of global REE reserves; potential shortages if demand surges beyond current production

Terbium (Tb): Master of Color and Precision Acoustics

Unique green luminescence + exceptional magnetostriction (Terfenol‑D).

Strategic applications: green phosphors, transducers, precision sensors/actuators (sonars).

Industrial interest: key for advanced electronics and defense; superior color/energy performance and advanced detection/control.

Risks & Substitutes

Limited availability and concentrated flows; sensitive to investment cycles.

Few equivalent substitutes for magnetostriction (Terfenol‑D is unique); design trade‑offs possible.

For green phosphors, potential substitutions by technology with color/efficiency compromises.

Related Materials

→ Dysprosium → Neodymium