Tl
metal· Tl
Thallium (Tl) is a soft, dense post-transition metal with low melting point and high toxicity, belonging to Group 13 of the periodic table. Historically used in specialized optical applications (infrared lenses, scintillation detectors) and legacy electronics, thallium has largely been phased out of most industrial applications due to severe health and environmental hazards; modern engineering selection favors safer alternatives. When encountered in active use, it typically appears in niche scientific instrumentation, certain photomultiplier tubes, or specialized research contexts where its unique optical and radiation properties justify the toxicity risks and regulatory constraints.
infrared optics and windowsradiation detection equipmentlegacy semiconductor researchspecialized scintillation detectorsresearch-phase applications only
Compliance & Regulations
?EAR?Conflict Free?RoHS?REACH?TSCA?Prop 65
| Property | Value | Unit | Conditions | Source | |
|---|---|---|---|---|---|
Bulk Modulus(K)2 entries | 26.38 | GPa | — | ||
| ↳ | 30.66 | GPa | — | ||
Elastic Compliance Tensor(Sij) | Matrix (redacted) | 1/GPa | — | ||
Elastic Anisotropy(AU) | 0.5403 | - | — | ||
Elastic Stiffness Tensor(Cij) | Matrix (redacted) | Pa | — | ||
Poisson's Ratio(ν)2 entries | 0.3809 | - | — | ||
| ↳ | 0.4100 | - | — | ||
Shear Modulus(G)2 entries | 6.823 | GPa | — | ||
| ↳ | 6.450 | GPa | — |
N entriesMultiple entries per property — large groups are collapsed; click a summary row to expand. Use filters above to narrow by form / heat treatment / basis.
Verified Unverified Low confidence (<80%) Link to source
| Property | Value | Unit | Conditions | Source | |
|---|---|---|---|---|---|
Density(ρ) | 11.10 | kg/m³ | — |
Verified Unverified Low confidence (<80%) Link to source
| Property | Value | Unit | Conditions | Source | |
|---|---|---|---|---|---|
Band Gap(Eg) | 0.000 | eV | — | ||
Magnetic Moment(μB) | 0.000 | µB | — | ||
Seebeck Coefficient(S) | -3.820 | µV/K | — |
Verified Unverified Low confidence (<80%) Link to source
| Property | Value | Unit | Conditions | Source | |
|---|---|---|---|---|---|
Energy Above Hull(ΔEhull) | 0.000 | eV/atom | — | ||
Formation Energy(ΔHf) | 0.000 | eV/atom | — |
Verified Unverified Low confidence (<80%) Link to source
Regulatory Screening
Environmental
Export Control
RoHS, REACH, and Prop 65 statuses are validated against official substance lists (ECHA SVHC Candidate List, OEHHA Prop 65, RoHS Annex II). Other regulations are estimated from composition and material classification. All screening is a starting point for due diligence — always verify with your supplier before making compliance decisions.