US 11,851,768 B2
Film-forming powder, film forming method, and film-forming powder preparing method
Yuji Kimura, Echizen (JP); Yasushi Takai, Echizen (JP); and Shigeyuki Nakamura, Echizen (JP)
Assigned to SHIN-ETSU CHEMICAL CO., LTD., Tokyo (JP)
Filed by Shin-Etsu Chemical Co., Ltd., Tokyo (JP)
Filed on Dec. 6, 2022, as Appl. No. 18/075,586.
Application 18/075,586 is a division of application No. 16/511,283, filed on Jul. 15, 2019, granted, now 11,549,185.
Claims priority of application No. 2018-134243 (JP), filed on Jul. 17, 2018.
Prior Publication US 2023/0100603 A1, Mar. 30, 2023
Int. Cl. C23C 24/02 (2006.01); C01F 17/259 (2020.01); C23C 24/08 (2006.01)
CPC C23C 24/02 (2013.01) [C01F 17/259 (2020.01); C23C 24/08 (2013.01); C01P 2004/51 (2013.01); C01P 2004/61 (2013.01); C01P 2004/62 (2013.01); C01P 2006/12 (2013.01)] 2 Claims
OG exemplary drawing
 
1. A method for preparing a film-forming powder comprising a rare earth oxyfluoride, the method comprising the steps of:
forming a rare earth ammonium fluoride complex salt on surfaces of rare earth oxide particles to provide precursor particles by forming a dispersion or slurry including rare earth oxide and ammonium fluoride, wherein the amount of ammonium fluoride in the dispersion or slurry is such that a ratio (B/A) of the number of moles (B) of fluorine in ammonium fluoride to the total number of moles (A) of rare earth elements in the dispersion is in the range 1≤B/A≤1.4, and
heat treating the precursor particles at a temperature of 350 to 700° C.