Corrosion resistance and antithrombogenic behavior of La and Nd ion implanted stainless steels

Abstract

Corrosion behavior of Zr modified CrN coatings using metal vapor vacuum arc ion implantation Structural modifications and corrosion behavior of martensitic stainless steel nitrided by plasma immersion ion implantation J. Vac. Sci. Technol. A 23, 693 (2005); 10.1116/1.1931681 Corrosion resistance of laser-fabricated metal-matrix composite layer on stainless steel 316L J. Laser Appl. 15, 107 (2003); 10.2351/1.1536649Process window and mechanism of surface property enhancement of 9Cr18 steel using plasma immersion ion implantation J.Lanthanide ions such as lanthanum ͑La͒ and neodymium ͑Nd͒ were implanted into 316 stainless steel samples using metal vapor vacuum arc to improve the surface corrosion resistance and antithrombogenic properties. X-ray photoelectron spectroscopy shows that lanthanum and neodymium exist in the +3 oxidation state in the surface layer. The corrosion properties of the implanted and untreated control samples were investigated utilizing electrochemical tests and our results show that La and Nd implantations enhance the surface corrosion resistance. In vitro activated partial thromboplastin time ͑APTT͒ tests were used to evaluate the antithrombogenic properties. The APTT time of the implanted samples was observed to be prolonged compared to that of the unimplanted stainless steel control. La and Nd ion implantations can be used to improve the surface corrosion resistance and biomedical properties of 316 stainless steels.

Structural and Chemical Studies of Metal–Organic Decomposed LaxCeyOz Thin Film as a Catalytic Oxide on 4H-SiC as a Function of Postdeposition Annealing Time

“…the main features of La 3d spectra (Figure ) are shown as T and T*, which represents 3d 5/2 and 3d 3/2 , respectively, with accompanying shakeup satellites, S and S* that arise due to electron transfer from O 2p to La 4f in photoelectron final state. − No obvious charging effect is observed for the La 3d spectra as a function of depth obtained for all of the samples annealed from 15 to 120 min (Figure ). This is a good indication to say that the substituted La 3+ ion is stable in the CeO 2 lattice.…”

“…Besides, the formation or removal of ligand holes in Ce 3+ or Ce 4+ could be possibly due to the localization of the ligand holes, in which the ligand hole will be transferred from the Ce 3+ site to Ce 4+ site or vice versa. The ligand holes can be also transferred from the Ce site to the La site in the La x Ce y O z solid solution, and this contributes to the final state configuration of La 3d (3d 9 4f 1 L 1 ). ,, While for the near-interface region, which is in the later Ar ion etching time, initially at 15 min, only the Ce 3+ doublets exist. Beyond the PDA time of 15 min, Ce 4+ doublets reappear.…”

“…46−48 u′ and v′ are the result of Ce 3d 9 4f 1 final state; u o and v o are the result of Ce 3d 9 4f 2 L 1 final state; u‴ and v‴ are the result of Ce 3d 9 4f 0 final state, while u, v, u″, and v″ are the result of Ce 3d 9 4f 2 L 2 and Ce 3d 9 4f 1 L 1 final states, 46,48,49 ligand holes can be also transferred from the Ce site to the La site in the La x Ce y O z solid solution, and this contributes to the final state configuration of La 3d (3d 9 4f 1 L 1 ). 44,45,51 While for the near-interface region, which is in the later Ar ion etching time, initially at 15 min, only the Ce 3+ doublets exist. Beyond the PDA time of 15 min, Ce 4+ doublets reappear.…”