First principles calculation of lithium adsorption and diffusion on stainless steel surface

doi:10.7523/j.ucas.2024.039

Abstract

Abstract:

The selection of divertor materials has always been one of the hot issues in the field of nuclear fusion. The experimental results in recent years show that using liquid lithium as plasma facing materials in divertor can not only effectively solve the problems faced by traditional solid materials， but also significantly improve the confinement property of plasma. However， the wettability of liquid lithium on the surface of most solid materials is not ideal. In view of this， the first-principles method was used to simulate and calculate the occupation and diffusion characteristics of lithium atoms on the surface of stainless steel， and the effects of nickel， tungsten， chromium and manganese were analyzed. The results show that the four alloying elements can significantly change the adsorption energy of lithium atoms on the （100） crystal plane. Around nickel and tungsten， the adsorption energy of lithium atom first increases and then decreases with the increase of distance， showing the effect of first attraction and then repulsion. However， around chromium and manganese， the adsorption energy decreases monotonously with the increase of distance， and it has a repulsive effect in the whole process. For nickel and tungsten， lithium atoms tend to diffuse in the direction close to alloy elements within a certain range， and move outward more easily beyond this range. For chromium and manganese， lithium atoms are always more likely to diffuse outward. The results of this paper are helpful to better understand the wetting and spreading characteristics of liquid lithium on the surface of stainless steel at the micro scale.

Key words: first-principles, adsorption energy, diffusion barrier, liquid lithium, stainless steel

CLC Number:

O485

Lei SHEN, Xingang YU. First principles calculation of lithium adsorption and diffusion on stainless steel surface[J]. Journal of University of Chinese Academy of Sciences, 2026, 43(4): 463-470.

Figures/Tables 9

Fig.1 Schematic diagram of atomic model

Fig.2 Three types of adsorption sites of Li atom on α-Fe （100） surface

Table 1 Adsorption energy of Li atom on α-Fe （100） surface

吸附点	覆盖率	吸附能/eV
吸附点	覆盖率	本文计算结果	文献数据
Hollow	1∶9	-0.24	-0.23^[26]
	1∶16	-0.32	—
	1∶36	-0.35	—
Bridge	1∶9	-0.11	-0.11^[26]
	1∶16	-0.23	—
	1∶36	-0.26	—
On-Top	1∶9	-0.02	-0.03^[26]
	1∶16	-0.17	—
	1∶36	-0.19	—

Fig.3 Two diffusion paths of Li atom on α-Fe （100）surface

Fig.4 Energy distribution of Li atom along two diffusion paths on α-Fe （100） surface

Fig.5 Adsorption sites of Li atoms on α-Fe （100） surface with an alloy element

Table 2 Adsorption energy of Li atom on α-Fe （100） surface with different substitutional alloy elements

吸附点	吸附能/eV
吸附点	Ni	W	Cr	Mn
H1	-0.41	-0.35	-0.26	-0.28
B	-0.34	-0.26	-0.08	—
O	-0.32	-0.04	0.13	0.18

Fig.6 Adsorption energy of Li atom at Hollow sites near the substitutional alloy element

Fig.7 Energy curve of Li atom on α-Fe （100） surface with a substitutional alloy element

References 27

[1]	Federici G， Skinner C H， Brooks J N， et al. Plasma-material interactions in current tokamaks and their implications for next step fusion reactors［J］. Nuclear Fusion， 2001， 41（12R）： 1967-2137. DOI： 10.1088/0029-5515/41/12/218 .
[2]	Roth J， Tsitrone E， Loarte A， et al. Recent analysis of key plasma wall interactions issues for ITER［J］. Journal of Nuclear Materials， 2009， 390-391： 1-9. DOI： 10.1016/j.jnucmat.2009.01.037 .
[3]	Nygren R E， Tabarés F L. Liquid surfaces for fusion plasma facing components：a critical review. Part I： Physics and PSI［J］. Nuclear Materials and Energy， 2016， 9： 6-21. DOI： 10.1016/j.nme.2016.08.008 .
[4]	Hu J S， Ren J， Sun Z， et al. An overview of lithium experiments on HT-7 and EAST during 2012［J］. Fusion Engineering and Design， 2014， 89（12）： 2875-2885. DOI： 10.1016/j.fusengdes.2014.06.015 .
[5]	Ono M， Bell M G， Kaita R， et al. Recent progress of NSTX lithium program and opportunities for magnetic fusion research［J］. Fusion Engineering and Design， 2012， 87（10）： 1770-1776. DOI： 10.1016/j.fusengdes.2011.10.011 .
[6]	Kugel H W， Allain J P， Bell M G， et al. NSTX plasma operation with a Liquid Lithium Divertor［J］. Fusion Engineering and Design， 2012， 87（10）：1724-1731. DOI： 10.1016/j.fusengdes.2011.07.010 .
[7]	S􀅡nchez J， Tabarés F L， Tafalla D， et al. Impact of lithium-coated walls on plasma performance in the TJ-II stellarator［J］. Journal of Nuclear Materials， 2009， 390： 852-857. DOI： 10.1016/j.jnucmat.2009.01.224 .
[8]	Wang H Y， Hu J S， Gao X， et al. Influence of Li and B coatings of metal walls on deuterium retention and plasma confinement in HT-7［J］. Nuclear Fusion， 2012， 52（10）： 103002. DOI： 10.1088/0029-5515/52/10/103002 .
[9]	Zuo G Z， Hu J S， Zhen S， et al. Comparison of various wall conditionings on the reduction of H content and particle recycling in EAST［J］. Plasma Physics and Controlled Fusion， 2011， 54（1）： 015014. DOI： 10.1088/0741-3335/54/1/015014 .
[10]	Kugel H W， Mansfield D， Maingi R， et al. Evaporated lithium surface coatings in NSTX［J］. Journal of Nuclear Materials， 2009， 390-391： 1000-1004. DOI： 10.1016/j.jnucmat.2009.01.262 .
[11]	Bell M G， Kugel H W， Kaita R， et al. Plasma response to lithium-coated plasma-facing components in the National Spherical Torus Experiment［J］. Plasma Physics and Controlled Fusion， 2009， 51（12）： 124054. DOI： 10.1088/0741-3335/51/12/124054 .
[12]	Lu W， Wang W H， Jiang H Y， et al. Investigation of wetting property between liquid lead lithium alloy and several structural materials for Chinese DEMO reactor［J］. Journal of Nuclear Materials， 2017， 494： 303-310. DOI： 10.1016/j.jnucmat.2017.07.055 .
[13]	Fiflis P， Press A， Xu W， et al. Wetting properties of liquid lithium on select fusion relevant surfaces［J］. Fusion Engineering and Design， 2014， 89（12）： 2827-2832. DOI： 10.1016/j.fusengdes.2014.03.060 .
[14]	Wang J Y， Wang H S， Xie J， et al. Fundamental study on the wetting property of liquid lithium［J］. Energy Storage Materials， 2018， 14： 345-350. DOI： 10.1016/j.ensm.2018.05.021 .
[15]	Hammouti S， Holybee B， Christenson M， et al. Wetting of liquid lithium on fusion-relevant materials microtextured by femtosecond laser exposure［J］. Journal of Nuclear Materials， 2018， 508： 237-248. DOI： 10.1016/j.jnucmat.2018.05.051 .
[16]	Cicero G， Calzolari A， Corni S， et al. Anomalous wetting layer at the Au（111） surface［J］. The Journal of Physical Chemistry Letters， 2011， 2（20）： 2582-2586. DOI： 10.1021/jz200989n .
[17]	Cui Y T， Liang F， Xu S， et al. Interfacial wetting behaviors of liquid Ga alloys/FeGa₃ based on metallic bond interaction［J］. Colloids and Surfaces A： Physicochemical and Engineering Aspects， 2019， 569： 102-109. DOI： 10.1016/j.colsurfa.2019.01.079 .
[18]	Yi S， Li G， Liu Z， et al. First-principles calculations on the wettability of Li atoms on the （111） surfaces of W and Mo substrates［J］. Plasma Physics Reports， 2018， 44（7）： 692-701. DOI： 10.1134/s1063780x18070097 .
[19]	Skinner C H， Capece A M， Roszell J P， et al. Spreading of lithium on a stainless steel surface at room temperature［J］. Journal of Nuclear Materials， 2016， 468： 26-30. DOI： 10.1016/j.jnucmat.2015.10.059 .
[20]	Kresse G， Joubert D. From ultrasoft pseudopotentials to the projector augmented-wave method［J］. Physical Review B， 1999， 59（3）： 1758-1775. DOI： 10.1103/PhysRevB.59.1758 .
[21]	Kresse G， Furthmüller J. Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set［J］. Physical Review B， 1996， 54（16）： 11169-11186. DOI： 10.1103/PhysRevB.54.11169 .
[22]	Kresse G， Furthmüller J. Efficiency of ab-initio total energy calculations for metals and semiconductors using a plane-wave basis set［J］. Computational Materials Science， 1996， 6（1）： 15-50. DOI： 10.1016/0927-0256（96）00008-0 .
[23]	Blöchl P E. Projector augmented-wave method［J］. Physical Review B， 1994， 50（24）： 17953-17979. DOI： 10.1103/physrevb.50.17953 .
[24]	Perdew J P， Ruzsinszky A， Tao J M， et al. Prescription for the design and selection of density functional approximations： more constraint satisfaction with fewer fits［J］. The Journal of Chemical Physics， 2005， 123（6）： 62201. DOI： 10.1063/1.1904565 .
[25]	Monkhorst H J， Pack J D. Special points for Brillouin-zone integrations［J］. Physical Review B， 1976， 13（12）： 5188-5192. DOI： 10.1103/PhysRevB.13.5188 .
[26]	Xu Y， Zhang Y， Li X， et al. The adsorption and dissolution properties of iron surfaces in liquid lithium and lead under a fusion environment［J］. Journal of Nuclear Materials， 2019， 524： 200-208. DOI： 10.1016/j.jnucmat.2019.06.033 .
[27]	Henkelman G， Uberuaga B P， Jónsson H. A climbing image nudged elastic band method for finding saddle points and minimum energy paths［J］. The Journal of Chemical Physics， 2000， 113（22）： 9901-9904. DOI： 10.1063/1.1329672 .