基底支撑刚度梯度变化对石墨烯层间摩擦力的影响
|
摘要
基于纳米摩擦能耗理论,利用分子动力学方法建立了公度接触下支撑刚度梯度变化的石墨烯层间摩擦力模型,分析了基底质心刚度和支撑刚度梯度变化对基底和薄片各接触区摩擦能耗的贡献.结果表明:软边界区始终贡献驱动力;硬边界区贡献的摩擦力最大,且随着支撑刚度的增大,硬边界区对总摩擦的贡献比也越高.各接触区的摩擦力是薄片和基底之间的褶皱势和接触区产生的法向变形差两部分的共同作用.前者是公度接触下阻碍滑移的界面势垒和刚度梯度方向上不同刚度支撑原子热振动引起的势梯度;后者是接触边界过渡区两侧原子的非对称变形和自由度约束突变引起的非平衡边界势垒相耦合的结果.本文对研究公度接触下刚度梯度支撑的纳米器件的相对运动规律有指导意义.
According to the molecular dynamics simulations and the mechanism of energy dissipation of nanofriction, we construct a model system with a flake sliding in commensurate configuration on a monolayer suspended graphene anchored on a bed of springs. The system is to analyze the contributions of different regions(T1–T7) of the graphene flake to friction force, with the substrate characterized by different stiffness gradients and midpoint stiffness.The results indicate that the soft region of contact(T1) always contributes to the driving force, whereas the hard region(T7) leads to the biggest friction force on all column atoms of the flake. Moreover, as the support stiffness increases, when the stiffness gradient and the midpoint stiffness are equal to 1.34 nN/nm~2 and 12 nN/nm, respectively,the contribution ratio of T7 to the total friction increases from 33% to 47%, which is approximately 4–15 times greater than those of each column atoms in T3–T6. The results also indicate that the energy barrier decreases with the increase of support stiffness along the stiffness gradient direction of the substrate, which induces the resistance forces on the relative motion to decrease. Meanwhile, the amplitude of the thermal atomic fluctuation is higher in the softer region while lower in the harder one. This difference in amplitude leads to the considerable potential gradient that ultimately causes the driving force. Finally, for a given point at the end of the flake(T1 or T7), the intensity of the van der Waals potential field is mainly determined by the nearest substrate atoms at that point. Part of these nearest atoms lie inside the contact region while the others do not. Consequently, the thermal vibration of the atoms inside the contact region is different from that of the atoms outside the confinement. The different thermal vibrations induce the greater edge barriers. In addition, T1 lies in the soft edge region and T7 in the hard one. As a result, the normal deformations of these two regions are always different, and therefore they also generate the driving force.At these points, the results reported here suggest that the friction force in each contact region is caused by the coupling of the energy barrier and the elastic deformation between the graphene surfaces. The former contribution,i.e.the energy barrier, includes the interfacial potential barrier in commensurate state which is against the sliding of the surfaces with respect to each other, and the potential gradient caused by the different vibration magnitudes of the substrate atoms against the different spring stiffness in the direction of stiffness gradient. The latter contribution, i.e.the elastic deformation, is the unbalanced edge energy barrier resulting from the asymmetrical deformation and the different degrees of freedom between the edge atoms of the slider and atoms inside and outside the contact area of the substrate. Results of this paper are expected to be able to provide theoretical guidance in considering the influence of stiffness gradient on friction between commensurate surfaces and in designing the nanodevices.
According to the molecular dynamics simulations and the mechanism of energy dissipation of nanofriction, we construct a model system with a flake sliding in commensurate configuration on a monolayer suspended graphene anchored on a bed of springs. The system is to analyze the contributions of different regions(T1–T7) of the graphene flake to friction force, with the substrate characterized by different stiffness gradients and midpoint stiffness.The results indicate that the soft region of contact(T1) always contributes to the driving force, whereas the hard region(T7) leads to the biggest friction force on all column atoms of the flake. Moreover, as the support stiffness increases, when the stiffness gradient and the midpoint stiffness are equal to 1.34 nN/nm~2 and 12 nN/nm, respectively,the contribution ratio of T7 to the total friction increases from 33% to 47%, which is approximately 4–15 times greater than those of each column atoms in T3–T6. The results also indicate that the energy barrier decreases with the increase of support stiffness along the stiffness gradient direction of the substrate, which induces the resistance forces on the relative motion to decrease. Meanwhile, the amplitude of the thermal atomic fluctuation is higher in the softer region while lower in the harder one. This difference in amplitude leads to the considerable potential gradient that ultimately causes the driving force. Finally, for a given point at the end of the flake(T1 or T7), the intensity of the van der Waals potential field is mainly determined by the nearest substrate atoms at that point. Part of these nearest atoms lie inside the contact region while the others do not. Consequently, the thermal vibration of the atoms inside the contact region is different from that of the atoms outside the confinement. The different thermal vibrations induce the greater edge barriers. In addition, T1 lies in the soft edge region and T7 in the hard one. As a result, the normal deformations of these two regions are always different, and therefore they also generate the driving force.At these points, the results reported here suggest that the friction force in each contact region is caused by the coupling of the energy barrier and the elastic deformation between the graphene surfaces. The former contribution,i.e.the energy barrier, includes the interfacial potential barrier in commensurate state which is against the sliding of the surfaces with respect to each other, and the potential gradient caused by the different vibration magnitudes of the substrate atoms against the different spring stiffness in the direction of stiffness gradient. The latter contribution, i.e.the elastic deformation, is the unbalanced edge energy barrier resulting from the asymmetrical deformation and the different degrees of freedom between the edge atoms of the slider and atoms inside and outside the contact area of the substrate. Results of this paper are expected to be able to provide theoretical guidance in considering the influence of stiffness gradient on friction between commensurate surfaces and in designing the nanodevices.
引文
[1]Krim J 1996 Sci.Am.275 74
[2]Ren S L,Yang S R,Zhao Y P 2003 Langmuir 19 2763
[3]Ren S L,Yang S R,Wang J Q,Liu W M,Zhao Y P2004 Chem.Mater.16 428
[4]Hu Y Z,Ma T B,Wang H 2013 Friction 1 24
[5]Liu S W,Wang H P,Xu Q,Ma T B,Yu G,Zhang C,Geng D,Yu Z,Zhang S,Wang W 2017 Nat.Commun.8 14029
[6]Ding L Y,Gong Z L,Huang P 2008 Acta Phys.Sin.576500(in Chinese)[丁凌云,龚中良,黄平2008物理学报57 6500]
[7]Lee C,Li Q,Kalb W,Liu X Z,Berger H,Carpick R W,Hone J 2010 Science 328 76
[8]Geim A K 2009 Science 324 1530
[9]de Wijn A S,Fusco C,Fasolino A 2010 Phys.Rev.E 81046105
[10]Xu Z,Li X,Yakobson B I,Ding F 2013 Nanoscale 56736
[11]Schedin F,Geim A,Morozov S,Hill E,Blake P,Katsnelson M,Novoselov K 2007 Nat.Mater.6 652
[12]Stoller M D,Park S,Zhu Y,An J,Ruoff R S 2008 Nano Lett.8 3498
[13]Lin Y M,Dimitrakopoulos C,Jenkins K A,Farmer DB,Chiu H Y,Grill A,Avouris P 2010 Science 327 662
[14]Yang J,Liu Z,Grey F,Xu Z,Li X,Liu Y,Urbakh M,Cheng Y,Zheng Q 2013 Phys.Rev.Lett.110 255504
[15]Wang J J,Wang F,Yuan P F,Sun Q,Jia Y 2012 Acta Phys.Sin.61 106801(in Chinese)[王建军,王飞,原鹏飞,孙强,贾瑜2012物理学报61 106801]
[16]Berman D,Erdemir A,Sumant A V 2014 Mater.Today17 31
[17]Koren E,L?rtscher E,Rawlings C,Knoll A W,Duerig U 2015 Science 348 679
[18]Liu Z,Yang J,Grey F,Liu J Z,Liu Y,Wang Y,Yang Y,Cheng Y,Zheng Q 2012 Phys.Rev.Lett.108 205503
[19]Bailey S,Amanatidis I,Lambert C 2008 Phys.Rev.Lett.100 256802
[20]Guo Z,Chang T,Guo X,Gao H 2012 J.Mech.Phys.Solids 60 1676
[21]Somada H,Hirahara K,Akita S,Nakayama Y 2008Nano Lett.9 62
[22]Shiomi J,Maruyama S 2009 Nanotechnology 20 055708
[23]Rurali R,Hernandez E 2010 Chem.Phys.Lett.497 62
[24]Chang T,Zhang H,Guo Z,Guo X,Gao H 2015 Phys.Rev.Lett.114 015504
[25]Filippov A E,Dienwiebel M,Frenken J W,Klafter J,Urbakh M 2008 Phys.Rev.Lett.100 046102
[26]Lebedeva I V,Knizhnik A A,Popov A M,Ershova O V,Lozovik Y E,Potapkin B V 2011 J.Chem.Phys.134104505
[27]Pálinkás A,Süle P,Szendr M,Molnár G,Hwang C,BiróL P,Osváth Z 2016 Carbon 107 792
[28]Woods C,Britnell L,Eckmann A,Ma R,Lu J,Guo H,Lin X,Yu G,Cao Y,Gorbachev R 2014 Nat.Phys.10451
[29]Lindsay L,Broido D A 2010 Phys.Rev.B 81 205441
[30]Lebedeva I V,Knizhnik A A,Popov A M,Ershova OV,Lozovik Y E,Potapkin B V 2010 Phys.Rev.B 82155460
[31]Plimpton S 1995 J.Comput.Phys.7 1
[32]Zhang H,Guo Z,Gao H,Chang T 2015 Carbon 94 60
[33]Smolyanitsky A,Killgore J P,Tewary V K 2012 Phys.Rev.B 85 035412
[34]Lee H,Lee N,Seo Y,Eom J,Lee S 2009 Nanotechnology20 325701
[35]Filleter T,McChesney J L,Bostwick A,Rotenberg E,Emtsev K,Seyller T,Horn K,Bennewitz R 2009 Phys.Rev.Lett.102 086102
[36]Xu L,Ma T B,Hu Y Z,Wang H 2011 Nanotechnology22 285708
[37]Wang Z J,Ma T B,Hu Y Z,Xu L,Wang H 2015 Friction3 170
[38]Li S,Li Q,Carpick R W,Gumbsch P,Liu X Z,Ding X,Sun J,Li J 2016 Nature 539 541
[39]Guo Z,Chang T,Guo X,Gao H 2011 Phys.Rev.Lett.107 105502
[40]Ma F,Zheng H,Sun Y,Yang D,Xu K,Chu P K 2012Appl.Phys.Lett.101 111904
[41]Chen J,Walther J H,Koumoutsakos P 2014 Nano Lett.14 819
[42]Zhang Y Y,Pei Q X,Jiang J W,Wei N,Zhang Y W2016 Nanoscale 8 483
[43]Barreiro A,Rurali R,Hernández E R,Moser J,Pichler T,Forro L,Bachtold A 2008 Science 320 775
[44]Zhao J,Huang J Q,Wei F,Zhu J 2010 Nano Lett.104309
[45]Cao Q,Han S J,Tulevski G S,Zhu Y,Lu D D,Haensch W 2013 Nat.Nanotechnol.8 180
[46]Gnecco E,Bennewitz R,Gyalog T,Loppacher C,Bammerlin M,Meyer E,Güntherodt H J 2000 Phys.Rev.Lett.84 1172
[47]Liu Y,Grey F,Zheng Q 2014 Sci.Rep.4 4875
[48]Berman D,Deshmukh S A,Sankaranarayanan S K,Erdemir A,Sumant A V 2015 Science 348 1118
[49]Seiler S,Halbig C E,Grote F,Rietsch P,B?rrnert F,Kaiser U,Meyer B,Eigler S 2018 Nat.Commun.9 836
[50]Ye Z,Tang C,Dong Y,Martini A 2012 J.Appl.Phys.112 116102
[51]Li Q,Lee C,Carpick R W,Hone J 2010 Phys.Status Solidi B 247 2909
[2]Ren S L,Yang S R,Zhao Y P 2003 Langmuir 19 2763
[3]Ren S L,Yang S R,Wang J Q,Liu W M,Zhao Y P2004 Chem.Mater.16 428
[4]Hu Y Z,Ma T B,Wang H 2013 Friction 1 24
[5]Liu S W,Wang H P,Xu Q,Ma T B,Yu G,Zhang C,Geng D,Yu Z,Zhang S,Wang W 2017 Nat.Commun.8 14029
[6]Ding L Y,Gong Z L,Huang P 2008 Acta Phys.Sin.576500(in Chinese)[丁凌云,龚中良,黄平2008物理学报57 6500]
[7]Lee C,Li Q,Kalb W,Liu X Z,Berger H,Carpick R W,Hone J 2010 Science 328 76
[8]Geim A K 2009 Science 324 1530
[9]de Wijn A S,Fusco C,Fasolino A 2010 Phys.Rev.E 81046105
[10]Xu Z,Li X,Yakobson B I,Ding F 2013 Nanoscale 56736
[11]Schedin F,Geim A,Morozov S,Hill E,Blake P,Katsnelson M,Novoselov K 2007 Nat.Mater.6 652
[12]Stoller M D,Park S,Zhu Y,An J,Ruoff R S 2008 Nano Lett.8 3498
[13]Lin Y M,Dimitrakopoulos C,Jenkins K A,Farmer DB,Chiu H Y,Grill A,Avouris P 2010 Science 327 662
[14]Yang J,Liu Z,Grey F,Xu Z,Li X,Liu Y,Urbakh M,Cheng Y,Zheng Q 2013 Phys.Rev.Lett.110 255504
[15]Wang J J,Wang F,Yuan P F,Sun Q,Jia Y 2012 Acta Phys.Sin.61 106801(in Chinese)[王建军,王飞,原鹏飞,孙强,贾瑜2012物理学报61 106801]
[16]Berman D,Erdemir A,Sumant A V 2014 Mater.Today17 31
[17]Koren E,L?rtscher E,Rawlings C,Knoll A W,Duerig U 2015 Science 348 679
[18]Liu Z,Yang J,Grey F,Liu J Z,Liu Y,Wang Y,Yang Y,Cheng Y,Zheng Q 2012 Phys.Rev.Lett.108 205503
[19]Bailey S,Amanatidis I,Lambert C 2008 Phys.Rev.Lett.100 256802
[20]Guo Z,Chang T,Guo X,Gao H 2012 J.Mech.Phys.Solids 60 1676
[21]Somada H,Hirahara K,Akita S,Nakayama Y 2008Nano Lett.9 62
[22]Shiomi J,Maruyama S 2009 Nanotechnology 20 055708
[23]Rurali R,Hernandez E 2010 Chem.Phys.Lett.497 62
[24]Chang T,Zhang H,Guo Z,Guo X,Gao H 2015 Phys.Rev.Lett.114 015504
[25]Filippov A E,Dienwiebel M,Frenken J W,Klafter J,Urbakh M 2008 Phys.Rev.Lett.100 046102
[26]Lebedeva I V,Knizhnik A A,Popov A M,Ershova O V,Lozovik Y E,Potapkin B V 2011 J.Chem.Phys.134104505
[27]Pálinkás A,Süle P,Szendr M,Molnár G,Hwang C,BiróL P,Osváth Z 2016 Carbon 107 792
[28]Woods C,Britnell L,Eckmann A,Ma R,Lu J,Guo H,Lin X,Yu G,Cao Y,Gorbachev R 2014 Nat.Phys.10451
[29]Lindsay L,Broido D A 2010 Phys.Rev.B 81 205441
[30]Lebedeva I V,Knizhnik A A,Popov A M,Ershova OV,Lozovik Y E,Potapkin B V 2010 Phys.Rev.B 82155460
[31]Plimpton S 1995 J.Comput.Phys.7 1
[32]Zhang H,Guo Z,Gao H,Chang T 2015 Carbon 94 60
[33]Smolyanitsky A,Killgore J P,Tewary V K 2012 Phys.Rev.B 85 035412
[34]Lee H,Lee N,Seo Y,Eom J,Lee S 2009 Nanotechnology20 325701
[35]Filleter T,McChesney J L,Bostwick A,Rotenberg E,Emtsev K,Seyller T,Horn K,Bennewitz R 2009 Phys.Rev.Lett.102 086102
[36]Xu L,Ma T B,Hu Y Z,Wang H 2011 Nanotechnology22 285708
[37]Wang Z J,Ma T B,Hu Y Z,Xu L,Wang H 2015 Friction3 170
[38]Li S,Li Q,Carpick R W,Gumbsch P,Liu X Z,Ding X,Sun J,Li J 2016 Nature 539 541
[39]Guo Z,Chang T,Guo X,Gao H 2011 Phys.Rev.Lett.107 105502
[40]Ma F,Zheng H,Sun Y,Yang D,Xu K,Chu P K 2012Appl.Phys.Lett.101 111904
[41]Chen J,Walther J H,Koumoutsakos P 2014 Nano Lett.14 819
[42]Zhang Y Y,Pei Q X,Jiang J W,Wei N,Zhang Y W2016 Nanoscale 8 483
[43]Barreiro A,Rurali R,Hernández E R,Moser J,Pichler T,Forro L,Bachtold A 2008 Science 320 775
[44]Zhao J,Huang J Q,Wei F,Zhu J 2010 Nano Lett.104309
[45]Cao Q,Han S J,Tulevski G S,Zhu Y,Lu D D,Haensch W 2013 Nat.Nanotechnol.8 180
[46]Gnecco E,Bennewitz R,Gyalog T,Loppacher C,Bammerlin M,Meyer E,Güntherodt H J 2000 Phys.Rev.Lett.84 1172
[47]Liu Y,Grey F,Zheng Q 2014 Sci.Rep.4 4875
[48]Berman D,Deshmukh S A,Sankaranarayanan S K,Erdemir A,Sumant A V 2015 Science 348 1118
[49]Seiler S,Halbig C E,Grote F,Rietsch P,B?rrnert F,Kaiser U,Meyer B,Eigler S 2018 Nat.Commun.9 836
[50]Ye Z,Tang C,Dong Y,Martini A 2012 J.Appl.Phys.112 116102
[51]Li Q,Lee C,Carpick R W,Hone J 2010 Phys.Status Solidi B 247 2909
© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号 地址：北京市海淀区学院路29号 邮编：100083 电话：办公室：(+86 10)66554848；文献借阅、咨询服务、科技查新：66554700 |