Terbium Oxide

Overview

Terbium Oxide (Tb₄O₇) is a dark brown powder celebrated for its dual role in optoelectronics and magnetism, serving as the primary source of Tb³+ ions. With a CAS number of 12037-01-3 and a molecular weight of 747.64 g/mol, this rare-earth oxide offers purity levels from 99.9% to 99.99% (4N), featuring a melting point of 2330°C and a density of 7.3 g/cm³. Its strong green fluorescence under UV excitation and high magnetic susceptibility make it indispensable in lighting, displays, and high-frequency magnetic devices.

Features

1. Bright Green Phosphorescence: Tb³+ ions emit intense green light at 545 nm when excited, critical for color-converting phosphors in LED and CRT displays.

2. Magnetic Anisotropy: High magnetocrystalline anisotropy enables use in terbium-doped iron garnets (TbIG) for microwave isolators and circulators.

3. Thermal Stability: Maintains structural integrity up to 2000°C, suitable for high-temperature phosphor applications in halogen lamps.

4. High Purity Control: Strict control of light rare-earth impurities like cerium and lanthanum (<0.1%) ensures consistent fluorescence purity and magnetic properties.

5. Solubility Flexibility: Partially soluble in inorganic acids to form Tb³+ solutions, facilitating wet-process synthesis of phosphors and magnetic fluids.

Applications

• LED Lighting: Serves as a green phosphor (e.g., Tb³+-doped aluminates), combining with blue chips and red phosphors to achieve white lighting with high color rendering index (CRI>90).

• Display Technologies: Used in the green fluorescent layer of CRT TVs and plasma displays, providing vibrant color reproduction and long-lasting luminescent performance.

• Magnetic Materials: Doped into ferrites to produce high-frequency magnetic cores, reducing eddy current losses in filters and transformers for 5G communication devices.

• Catalysis: Acts as a catalyst support for automotive exhaust treatment, enhancing the activity and poison resistance of NOx reduction reactions.

• Medical Research: The fluorescent properties of Tb³+ ions are utilized in bi test kits for time-resolved fluoroimmunoassay (TRFIA), enabling ultrasensitive detection of disease markers.

FAQ

Q: Is there any export limitation for the material Tb4O7 in China?

A: Since April 2025, our country put Terbium as dual use item, which is under strict export limitation in China.

But the export licence can be possibly permitted if the end user and end user are not related with military use.

Q: What is the difference between Tb₄O₇ and TbO₂?

A: Tb₄O₇ is the most stable oxidation state with mixed valence (Tb³+/Tb⁴+), while TbO₂ is a dioxide mainly used in special redox reactions, with different application scenarios.

Q: Can Terbium Oxide be used in outdoor lighting?

A: Yes, its strong resistance to UV aging makes it suitable for preparing phosphors for streetlights and tunnel lights, maintaining luminous efficiency in humid and high-temperature environments.

Q: How is the particle size optimized for phosphor synthesis?

A: Typically provides 1-5μm spherical particles with surface coating of silicon or aluminum to improve dispersibility and anti-deliquescence, suitable for high-temperature solid-phase reactions.

Q: Are there radiation risks associated with Terbium Oxide?

A: No, the fluorescence excitation of Tb³+ ions is based on UV absorption, and the material itself is non-radioactive, complying with EU RoHS and US FDA safety standards.

Q: What is the shelf life of Terbium Oxide?

A: Under sealed storage conditions (<25°C, humidity <40%), the shelf life can reach 5 years. After opening, it is recommended to use it within 6 months to avoid moisture absorption.