Lithium-containing thiostannate spinels for thermal neutron and alpha-particle detection
Lithium-containing thiostannate spinel compounds having the formula Li 2 M 1+x Sn 3−x S 8 , where x is 0 or 1 and M is Mg, Fe, Mn, Ni, Ga, In, or a combination thereof; or the formula Li 1.66 CuSn 3.33 S 8 are provided. Methods and devices for detecting incident neutrons and alpha-particles using the compounds are also provided. For thermal neutron detection applications, the compounds can be enriched with lithium-6 isotope ( 6 Li) to enhance their neutron detecting capabilities.
1. A lithium-containing thiostannate compound having a three-dimensional cubic spinel structure and the formula: Li 2 M 1+x Sn 3-x S 8 , where 0≤x≤1 and M is Mg, Fe, Mn, Ni, Ga, In or a combination thereof; or Li 1.66 CuSn 3.33 S 8 .
2. The lithium-containing thiostannate compound of claim 1 , wherein the Li in the lithium-containing thiostannate compound comprises 6 Li.
3. The lithium-containing thiostannate compound of claim 1 , wherein the compound is in the form of a single-crystal.
4. The lithium-containing thiostannate compound of claim 1 , having the formula Li 2 MgSn 3 S 8 .
5. The lithium-containing thiostannate compound of claim 1 , having the formula Li 2 NiSn 3 S 8 .
6. The lithium-containing thiostannate compound of claim 1 , having the formula Li 2 MnSn 3 S 8 .
7. The lithium-containing thiostannate compound of claim 1 , having the formula Li 1.66 CuSn 3.33 S 8 .
8. A neutron or alpha-particle detector comprising:
a material comprising a lithium-containing thiostannate compound having a three-dimensional cubic spinel structure and the formula: Li 2 M 1+x Sn 3−x S 8 , where x is 0 or 1 and M is Mg, Fe, Mn, Ni, Ga, In or a combination thereof, or Li 1.66 CuSn 3.33 S 8 ;
a first electrode in electrical communication with the material; and
a second electrode in electrical communication with the material, wherein the first and second electrodes are configured to apply an electric field across the material.
9. The detector of claim 8 , wherein the Li in the lithium-containing thiostannate compound comprises 6 Li.
10. The detector of claim 8 , wherein the lithium-containing thiostannate compound has the formula Li 2 MgSn 3 S 8 .
11. The detector of claim 8 , wherein the lithium-containing thiostannate compound has the formula Li 2 NiSn 3 S 8 .
12. The detector of claim 8 , wherein the lithium-containing thiostannate compound has the formula Li 2 MnSn 3 S 8 .
13. The detector of claim 8 , wherein the lithium-containing thiostannate compound has the formula Li 1.66 CuSn 3.33 S 8 .
14. The detector of claim 8 , further comprising:
a readout circuit coupled to the electrodes for detecting electrical signals generated when a neutron or alpha particle interacts with the lithium-containing thiostannate compound; and
an imaging system coupled to the readout circuit for processing signals from the readout circuit and generating an image of a neutron-emitting object or alpha-particle-emitting object being imaged by the detector.
15. A method for detecting neutrons or alpha particles, the method comprising:
applying an electric field across a lithium-containing thiostannate compound having a three-dimensional cubic spinel structure and the formula: Li 2 M 1+x Sn 3−x S 8 , where x is 0 or 1 and M is Mg, Fe, Mn, Ni, Ga, In or a combination thereof; or Li 1.66 CuSn 3.33 S 8 ;
exposing the lithium-containing thiostannate compound to incident neutrons or alpha particles, wherein the lithium-containing thiostannate compound absorbs incident neutrons or alpha particles, resulting in the generation of an electrical signal; and
detecting the electrical signal.
16. The method of claim 15 , wherein the Li comprises 6Li.
17. The method of claim 15 , wherein the lithium-containing thiostannate compound has a DC electrical resistivity in the range from 1.0×10 6 Ωcm −1 to 2.5×10 7 Ωcm −1 .
18. The method of claim 15 , wherein the lithium-containing thiostannate compound has an optical bandgap in the range from 0.9 eV to 2.3 eV.
19. The method of claim 15 , wherein the Li in the lithium-containing thiostannate compound comprises 6 Li.
20. The method of claim 15 , wherein the lithium-containing thiostannate compound is selected from Li 2 MgSn 3 S 8 , Li 2 NiSn 3 S 8 , Li 2 MnSn 3 S 8 , and Li 1.66 CuSn 3.33 S 8 .