Samarium Nitrate, Samarium Trinitrate, Samarium Nitrate Hydrate, 10361‑83‑8

Samarium Nitrate, Samarium Trinitrate, Samarium Nitrate Hydrate, 10361‑83‑8

SAMARIUM(III) NITRATE (HYDRATE) 

Chemical Name: Samarium(III) Nitrate / Samarium Trinitrate
CAS Number: 10361-83-8
EC Number: 233-814-1
HS Code: 283429

1. PRODUCT IDENTIFICATION AND CHEMICAL IDENTITY

2. CHEMICAL STRUCTURE AND EXPLANATION

Chemical Structure and Bonding:

Samarium(III) Nitrate is an ionic compound composed of one Samarium (Sm³⁺) cation and three Nitrate (NO₃⁻) anions. Samarium is in the +3 oxidation state (trivalent) in this compound. The molecule contains a variable number of water molecules of crystallization (typically 6 molecules - hexahydrate). The characteristic light yellow color is due to the Sm³⁺ ion's electronic transitions.

Molecular Formula Representation:

Sm(NO₃)₃·6H₂O (hexahydrate form)

This formula indicates the following structure:

• 1 Samarium ion (Sm³⁺): Central metal atom.

• 3 Nitrate groups (NO₃⁻): Trigonal planar anions.

• 6 Water molecules (H₂O): Water of crystallization bound to the crystal lattice.

Crystal Structure and Ionic Arrangement:

In the crystal structure, the Sm³⁺ ion is coordinated by oxygen atoms from nitrate groups and water molecules (typically 9-coordinate). Nitrate ions act as bridges between samarium centers. The six water molecules are part of the crystal structure and impart specific thermal stability and solubility characteristics to the compound. Upon heating, these water molecules are sequentially removed (dehydration), eventually forming the anhydrous form.

Simplified Ionic Representation:

        Sm³⁺   NO₃⁻   H₂O
          \     /       /
           Sm(NO₃)₃ · 6H₂O
          /     \       \
        NO₃⁻   NO₃⁻   H₂O

(An ionic crystal lattice composed of 1 Sm³⁺ ion, 3 NO₃⁻ ions, and 6 water molecules)

Structural Properties:

Dehydration (Loss of Water upon Heating):

Samarium Nitrate Hydrate loses water sequentially when heated:

Sm(NO₃)₃·6H₂O → Sm(NO₃)₃·xH₂O → Sm(NO₃)₃ (anhydrous)

At higher temperatures, the nitrate groups decompose to form samarium oxide (Sm₂O₃) and nitrogen oxides (NOx).

3. PHYSICAL AND CHEMICAL PROPERTIES

Important Physical Notes:

• Samarium Nitrate has a characteristic light yellow color due to the Sm³⁺ ion's f-f electronic transitions.

• It is highly hygroscopic and rapidly absorbs moisture from the air, requiring special packaging and storage conditions.

• It has a low melting point (~60°C); when heated, it dissolves in its own water of crystallization, forming a clear liquid.

• It has high solubility in water and ethanol, making it suitable for various applications.

• It exhibits oxidizing properties due to nitrate ions. Contact with organic materials should be avoided.

• High purity grades (≥ 99.9%) are available in rare earth element purity.

4. CHEMICAL PROPERTIES AND REACTIONS

Important Reactions:

1. Thermal Decomposition:

This reaction is the primary method used for producing samarium oxide.

First, dehydration:
Sm(NO₃)₃·6H₂O → Sm(NO₃)₃ + 6H₂O (approximately 60-200°C)

Then, thermal decomposition:
4 Sm(NO₃)₃ → 2 Sm₂O₃ + 12 NO₂ + 3 O₂ (high temperature, >600°C)

2. Reaction with Bases (Precipitation):

Samarium hydroxide precipitates, which can be used as an intermediate in samarium oxide production.

Sm(NO₃)₃ + 3 NaOH → Sm(OH)₃ ↓ + 3 NaNO₃

3. Dissolution and Hydrolysis in Water:

Hydrolysis of samarium ions causes the solution to become acidic.

Sm³⁺ + H₂O ⇌ Sm(OH)²⁺ + H⁺

4. Reduction to Sm²⁺:

Sm³⁺ can be reduced to Sm²⁺ using strong reducing agents:

Sm³⁺ + e⁻ → Sm²⁺ (E° ≈ -1.55 V)

This property is important in certain optical and magnetic applications.

5. Precipitation with Oxalate:

2 Sm(NO₃)₃ + 3 (NH₄)₂C₂O₄ → Sm₂(C₂O₄)₃ ↓ + 6 NH₄NO₃

5. APPLICATIONS AND INDUSTRIAL USES

5.1. Permanent Magnets (Most Important Application)

Samarium compounds, particularly Samarium-Cobalt (SmCo₅ and Sm₂Co₁₇) magnets, are critical in high-performance permanent magnet applications. These magnets offer excellent temperature stability and corrosion resistance. Samarium Nitrate is a precursor for these magnet materials.

5.2. Phosphors and Luminescent Materials

Samarium compounds are used in phosphors and luminescent materials for their unique optical properties, particularly orange-red emission.

5.3. Catalyst Applications

5.4. Advanced Ceramics and Materials

5.5. Nuclear Technology

Samarium isotopes (particularly ¹⁴⁹Sm) have high neutron absorption cross-sections and can be used as neutron absorbers.

5.6. Rare Earth Synthesis and Laboratory

6. SECTORAL SUITABILITY TABLE

7. SAFETY AND TOXICOLOGY

Safety Precautions:

• Keep away from heat, sparks, and open flames.

• Store separately from combustible materials.

• Avoid dust formation.

• Work in well-ventilated areas.

• Use protective gloves, safety goggles, and dust mask.

• Wash hands thoroughly after handling.

• In case of eye contact, rinse with plenty of water for at least 15 minutes and seek medical attention.

• Avoid contact with organic materials.

8. STORAGE AND HANDLING

9. TRANSPORT AND REGULATORY INFORMATION

10. QUALITY AND PURITY

11. RAW MATERIALS AND DOWNSTREAM PRODUCTS

11.1. Raw Materials (Upstream)

11.2. Downstream Products

12. FIRST AID MEASURES

13. FIREFIGHTING MEASURES

14. ACCIDENTAL RELEASE MEASURES

15. SUMMARY AND CRITICAL WARNINGS

SUMMARY:

Samarium(III) Nitrate (Sm(NO₃)₃·xH₂O, CAS 10361-83-8) is an inorganic salt composed of one Samarium (Sm³⁺) and three Nitrate (NO₃⁻) ions, containing a variable number of water molecules of crystallization (typically hexahydrate). It appears as a light yellow crystalline solid, is highly soluble in water and ethanol, and is hygroscopic (moisture-absorbing). The light yellow color is characteristic of Sm³⁺ ions.

Its most critical application is as a precursor for Samarium-Cobalt (SmCo) permanent magnets, which are essential in aerospace, defense, and high-temperature industrial applications. It is also used in phosphors and luminescent materials, catalysts, advanced ceramics, and nuclear technology (as a neutron absorber).

Under GHS classification, it is an oxidizer and harmful (H272, H302, H315, H319). Due to nitrate ions, it exhibits oxidizing properties and must be kept away from organic/reducing substances. Due to its hygroscopic nature, it must be stored in a cool, dry environment in tightly closed packaging. Appropriate Personal Protective Equipment (PPE) must be used during handling to avoid inhalation of dust and contact with skin/eyes.

Key Properties:

CRITICAL WARNINGS:

1. Oxidizing Property: Exhibits oxidizing properties due to nitrate ions. Contact with organic materials, reducing agents, and combustible materials must be avoided. May intensify fire (H272). Therefore, it must be stored separately and away from combustible and reducing materials.

2. Hygroscopic Property and Moisture Sensitivity: Highly hygroscopic and rapidly absorbs moisture from the air. Storage and weighing operations must not be performed in humid environments. After opening, the container must be quickly resealed and storage under an inert atmosphere (nitrogen, argon) is preferred. Moisture absorption compromises weighing accuracy and stoichiometry. The yellow color may fade or change if the compound absorbs significant moisture.

3. Low Melting Point and Thermal Instability: Melts at approximately 60°C by dissolving in its own water of crystallization. This is an important property to consider during thermal processes. At higher temperatures, nitrate groups decompose, releasing toxic nitrogen oxides (NO, NO₂). Thermal processes should be conducted in well-ventilated areas or under fume hoods.

4. Hydrated Structure and Stoichiometry: Contains six molecules of water of crystallization. Different hydration states have different molecular weights. The specific hydrate form must be confirmed when ordering and using the product. Stoichiometric calculations must account for the water content.

5. Structure and Purity: High purity (≥ 99.9%) is critical for magnet, phosphor, optical, and nuclear applications. Even trace amounts of other rare earth elements can significantly affect magnetic, luminescent, or optical properties. Purity specifications must be carefully verified for critical applications.

6. Color Stability and Optical Properties: The optical and magnetic properties of samarium compounds depend on the oxidation state (Sm³⁺ vs. Sm²⁺). Samarium Nitrate contains Sm³⁺. Heating in a reducing atmosphere can convert it to Sm²⁺, which has different optical and magnetic properties. Care must be taken in processing to achieve the desired samarium oxidation state.

7. Dust Control: The powder form can irritate the lungs if inhaled. Dust control measures must be implemented in the work area (closed systems, local exhaust ventilation) and appropriate respiratory protection (dust mask or N95/FFP2) must be used.

8. Aqueous Solution Acidity: Aqueous solutions are acidic due to hydrolysis. Appropriate protective equipment should be used when working with acidic solutions, and base solutions should be available for neutralization.

9. Environmental Precautions: As a water-soluble salt, release into the environment (particularly water sources) must be prevented. Samarium compounds may exhibit toxic effects in aquatic environments. Waste solutions must not be discharged into sewers and must be disposed of according to local regulations.

10. Regulatory Compliance: Registration and notification requirements under REACH and KKDİK must be observed. It is classified as Class 5.1 (Oxidizing substance) under ADR/IMDG/IATA, requiring special labeling and documentation during transport. Use in food, cosmetics, and textile sectors is strictly prohibited.

11. Special Warning for Magnet Applications: For Samarium-Cobalt magnet production, purity is absolutely critical. Impurities such as iron, nickel, and other transition metals can dramatically reduce magnetic performance. The nitrate decomposition conditions (temperature, atmosphere) must be carefully controlled to achieve the correct phase formation (SmCo₅ or Sm₂Co₁₇).

12. Special Warning for Nuclear Applications: For nuclear applications, isotopic purity may be important. Samarium-149 has a particularly high neutron absorption cross-section. The natural isotopic composition of samarium should be confirmed for nuclear applications. Additionally, residual nitrate content must be minimized for reactor applications.

13. Special Warning for Phosphor Applications: The orange-red emission from Sm³⁺ depends on the host crystal structure. Synthesis conditions must be optimized to achieve efficient luminescence. Residual nitrates can quench luminescence and should be completely decomposed.

14. Recycling and Waste: Samarium is a critical raw material. Recovery and recycling of samarium from waste magnets, phosphors, and other materials should be considered to ensure sustainable supply and reduce environmental impact.

Disclaimer: This Technical Data Sheet (TDS) is for informational purposes only. The information provided is based on available data and is believed to be accurate. However, the user is solely responsible for determining the suitability of the product for their specific applications and for complying with all applicable regulations and safety requirements. For complete safety, handling, storage, and regulatory compliance information, always refer to the official Safety Data Sheet (SDS/MSDS) provided by the manufacturer/supplier. Users are responsible for testing the product in their own processes and applications. All local, national, and international regulations must be followed when working with Samarium(III) Nitrate.