Sodium iodide (NaI) is an ionic ceramic compound formed from sodium and iodine, belonging to the halide salt family with a rock-salt crystal structure. It is primarily used as a scintillation detector material in radiation detection systems, where its high stopping power for gamma rays and excellent light output make it the standard choice for medical imaging (PET/SPECT scanners), nuclear spectroscopy, and radiation monitoring equipment. NaI is valued for its superior energy resolution and detection efficiency compared to alternatives like plastic scintillators, though it requires careful handling due to hygroscopic properties and is often used in thallium-doped form (NaI:Tl) to enhance luminescence efficiency.
Compliance & Regulations
| Property | Value | Unit | Conditions | Source | |
|---|---|---|---|---|---|
Bulk Modulus(K)3 entries | 15.76 | GPa | — | ||
| ↳ | 15.76 | GPa | — | ||
| ↳ | 17.93 | GPa | — | ||
Elastic Compliance Tensor(Sij) | Matrix (redacted) | 1/GPa | — | ||
Elastic Anisotropy(AU) | 0.2333 | - | — | ||
Elastic Stiffness Tensor(Cij) | Matrix (redacted) | Pa | — | ||
Poisson's Ratio(ν)2 entries | 0.2722 | - | — | ||
| ↳ | 0.2600 | - | — | ||
Shear Modulus(G)3 entries | 8.465 | GPa | — | ||
| ↳ | 8.465 | GPa | — | ||
| ↳ | 10.88 | GPa | — |
| Property | Value | Unit | Conditions | Source | |
|---|---|---|---|---|---|
Density(ρ) | 3.746 | kg/m³ | — |
| Property | Value | Unit | Conditions | Source | |
|---|---|---|---|---|---|
Band Gap(Eg)2 entries | 5.800 | eV | — | ||
| ↳ | 3.851 | eV | — | ||
Dielectric Constant (Relative Permittivity)(εr)3 entries | 8.360 | - | — | ||
| ↳ | 7.087 | - | — | ||
| ↳ | 5.424 range 3.488–7.359median of 2 measurements | - | — | ||
Electronic Dielectric Tensor(ε∞) | Matrix (redacted) | - | — | ||
Total Dielectric Tensor(ε) | Matrix (redacted) | - | — | ||
Magnetic Moment(μB) | 0.000 | µB | — | ||
Piezoelectric Modulus(eij) | 0.000 | C/m² | — | ||
Seebeck Coefficient(S) | -77.72 | µV/K | — |
| Property | Value | Unit | Conditions | Source | |
|---|---|---|---|---|---|
Energy Above Hull(ΔEhull) | 0.00900 | eV/atom | — | ||
Formation Energy(ΔHf)2 entries | -1.492 | eV/atom | — | ||
| ↳ | -1.358 | eV/atom | — |