Lithium lanthanum zirconate thin films
Forming a lithium lanthanum zirconate thin film includes disposing zirconium oxide on a substrate to yield a zirconium oxide coating, contacting the zirconium oxide coating with a solution including a lithium salt and a lanthanum salt, heating the substrate to yield a dried salt coating on the zirconium oxide coating, melting the dried salt coating to yield a molten salt mixture, reacting the molten salt mixture with the zirconium oxide coating to yield lithium lanthanum zirconate, and cooling the lithium lanthanum zirconate to yield a lithium lanthanum zirconate coating on the substrate. In some cases, the zirconium oxide coating is contacted with an aqueous molten salt mixture including a lithium salt and a lanthanum salt, the molten salt mixture is reacted with the zirconium oxide coating to yield lithium lanthanum zirconate, and the lithium lanthanum zirconate is cooled to yield a lithium lanthanum zirconate coating on the substrate.
1. A method of coating a substrate, the method comprising:
disposing zirconium oxide on a substrate to yield a zirconium oxide coating on the substrate;
heating an aqueous mixture comprising a lithium salt and a lanthanum salt to yield a molten salt mixture;
contacting the zirconium oxide coating with the molten salt mixture;
reacting the molten salt mixture with the zirconium oxide coating to yield lithium lanthanum zirconate; and
cooling the lithium lanthanum zirconate to yield a lithium lanthanum zirconate coating on the substrate.
2. The method of claim 1 , wherein contacting the substrate with the molten salt mixture comprises immersing the substrate in the molten salt mixture.
3. The method of claim 1 , wherein the aqueous mixture further comprises a zirconium salt.
4. The method of claim 1 , wherein disposing zirconium oxide on the substrate comprises atomic layer deposition or plasma-enhanced atomic layer deposition of zirconium oxide on the substrate.
5. The method of claim 4 , wherein disposing the zirconium oxide on the substrate further comprises disposing additional zirconium oxide on the zirconium oxide coating with a chemical vapor deposition or sol-gel process.
6. The method of claim 1 , wherein disposing the zirconium oxide on the substrate comprises disposing zirconium oxide nanoparticles on the substrate.
7. The method of claim 6 , further comprising preparing the zirconium oxide nanoparticles by a sol-gel precipitation reaction comprising zirconium butoxide.
8. The method of claim 1 , wherein the zirconium oxide coating is amorphous.
9. The method of claim 1 , wherein the aqueous mixture is homogeneous.
10. The method of claim 1 , wherein the lithium salt comprises lithium nitrate.
11. The method of claim 1 , wherein the lanthanum salt comprises lanthanum nitrate.
12. The method of claim 1 , wherein the aqueous mixture further comprises a zirconium salt.
13. The method of claim 12 , wherein the zirconium salt comprises a nitrate salt.
14. The method of claim 1 , wherein the molten salt mixture comprises one or more metal dopants.
15. The method of claim 14 , wherein the metal dopants comprise salt precursors, oxidic precursors, or any combination thereof.
16. The method of claim 14 , wherein the metal dopants comprise aluminum, gallium, tantalum, or any combination thereof.
17. The method of claim 1 , wherein the molten salt mixture comprises halide, carbonate, nitrate, peroxide, or hydroxide salts, or any combination thereof.
18. The method of claim 1 , wherein reacting the molten salt mixture with the zirconium oxide coating to yield the lithium lanthanum zirconate occurs at a temperature in a range of 400° C. to 800° C.