中科大材料科学课件02原子结构与原子间键结

原子模式量子力学原理图示吸引力、排斥力与最终的能量平衡距离与结合能量离子、共价、金属、氢、vanderWaals键结展示各种键结的材料第二章原子结构与原子间键结

Fe原子在Cu基板上原子像(IBM)CO原子在Pt基板上原子像(IBM)Xe原子在Ni基板上原子像(IBM)基本观念(一)

原子结构电荷：1.60x10-19C中子重量1.67x10-27kg(p,n)，9.11x10-31kg(e)基本观念(二)

尺寸原子序：Z，钸（94，Pu）同位素：Z，N原子质量单位：A=12.00000forC12

1.Namethetwoatomicmodelscited,andnotethedifferencesbetweenthem.2..Describetheimportantquantum-mechanicalprinciplethatrelatestoelectronenergies.3.(a)Namethefourelectronquantumnumbers. (b)Foraspecificelectron,notewhateachofitsquantumnumbersdetermines.4..4.WriteadefinitionofthePauliexclusionprinciple.5.Writethegeneralcharacteristicsoftheelementsthatarearrayedineachcolumnoftheperiodictable.6.Writetheequationthatrelatesenergyandforce.7.

7.(a)Schematicallyplotattractive,repulsive,andnetenergiesversusinteratomicseparationfortwoatomsorions. (b)Nownoteonthisplottheequilibriumseparationandthebondingenergy.8.(a)Brieflydescribeionic,covalent,metallic,hydrogen,andvanderWaal'sbonds. (b)Nownotewhatmaterialsexhibiteachofthesebondingtypes.9.Giventhechemicalformulaforamaterial,beabletocitewhatbondingtype(s)is(are)possible.10.Giventheelectronegativitiesoftwoelements,computethepercentioniccharacterofthebondthatformsbetweenthem.11.Definewhatismeantbytheterm"molecule".J.J.ThomsonCathodeRayTubeMaxPlanck(1858-1947)

MaxKarlErnstLudwigPlanck

TheNobelPrizeinPhysics1918"inrecognitionoftheservicesherenderedtotheadvancementofPhysicsbyhisdiscoveryofenergyquanta"ErnestRutherford(1871-1937)ErnestRutherford(1871-1937)

TheNobelPrizeinChemistry1908"forhisinvestigationsintothedisintegrationoftheelements,andthechemistryofradioactivesubstances"NielsHenrikDavidBohrNielsHenrikDavidBohrTheNobelPrizeinPhysics1922"forhisservicesintheinvestigationofthestructureofatomsandoftheradiationemanatingfromthem"PrinceLouisdeBroglie

(1892-1987)

PrinceLouis-VictorPierreRaymonddeBroglie

TheNobelPrizeinPhysics1929"forhisdiscoveryofthewavenatureofelectrons"ErwinSchrödinger(1887-1961)ErwinSchrödingerTheNobelPrizeinPhysics1933"forthediscoveryofnewproductiveformsofatomictheory"WERNERHEISENBERG(1901-1976)WernerKarlHeisenberg

TheNobelPrizeinPhysics1932"forthecreationofquantummechanics,theapplicationofwhichhas,interalia,ledtothediscoveryoftheallotropicformsofhydrogen"电子组态（electronconfiguration）

电子能态（energystate）最低能态（groundstate）Pauli互斥原理（Pauliexclusionprinciple）电子组态：原子结构，电子能态占据的方式WolfgangPauli(1900-1958)WolfgangPauli(1900-1958

TheNobelPrizeinPhysics1945"forthediscoveryoftheExclusionPrinciple,alsocalledthePauliPrinciple"电子组态

价电子（valenceelectron）稳定电子组态（stableelectronconfiguration）混合spn

轨域（hybridspnorbital），n=1,2,3量子数

主要（principal,n）量子数：K,L,M,N,O：距离次（subshell,l）量子数：s,p,d,f,1ton：形状磁（magnetic,m）量子数：-(l-1)to+(l-1)自旋（spin,s）量子数：-1/2,+1/21s2py3s3py3dxz4py4dxzLi（3）：1s22s1Na（11）：1s22s22p63s1K（19）：1s22s22p63s23p64s1Sc（21）：1s22s22p63s23p63d14s2Zn（30）：1s22s22p63s23p63d104s2Kr（36）：1s22s22p63s23p63d104s24p6键结力与能量

吸引力、排斥力，净力吸引能、排斥能，净能键结能力、能量与原子间距离曲线键结能大：熔点高室温：固体、液体、气体力与原子间距离曲线：刚硬度能量与原子间距离曲线：热膨胀离子键：存在于紧邻而带相反电荷离子之库伦原子间键结NaCl,MgO库伦静电力EA=-A/r,ER=B/rn

(n~8)Non-directional3-8eV/atom晶质与非晶质

共价键：紧邻原子共享电子之原子间键结diamond,Si,Ge,GaAs,InSb,SiC,H2,Cl2,F2,CH4,H2O,HNO3,HF特定方向,8-N’键强(diamond)或弱(Bi)高分子材料离子与共价键周期表中相对位置，阴电性距离愈远，阴电性差愈大，离子键性愈强%离子键性={1-exp[-(0.25)(XA-XB)2]}x100金属键：在金属固体中所有原子共享不限于局部价电子之原子间键电子海,电子云，黏胶离子核心.不具方向性0.7eV/atomforHg,8.8eV/atomforW良导体，延展性好JohannesDiderikVanderWaals(1837–1923)JohannesDiderikvanderWaals

TheNobelPrizeinPhysics1910"forhisworkontheequationofstateforgasesandliquids"水：独特的外形与构成赋予水近乎魔术般的力量（米老鼠、熊宝宝）令人清新有劲的古董（数十亿年）最神奇、多变的物质氢键：如磁铁相吸惊人的溶解力：第一溶剂，溶解地表上下所有物质酸雨、灌溉水分子间强大吸引力：毛细现象微血管2%：口渴，7%：脱水死亡

The2001NobelPrizeinPhysics"fortheachievementofBose-Einsteincondensationindilutegasesofalkaliatoms,andforearlyfundamentalstudiesofthepropertiesofthecondensates".

Bose-Einsteincondensate(BEC,波色－爱因斯坦冷凝物)EricA.Cornell（39），WolfgangKetterle（43），CarlE.Wieman（50）Bose-Einsteincondensate

1995,CornellandWieman

apurecondensateofabout2000rubidiumatomsat20nK(nanokelvin),

Ketterle：sodiumatoms.Thecondensateshemanagedtoproducecontainedmoreatomsandcouldthereforebeusedtoinvestigatethephenomenonfurther.

``Ihopedthatonedaythismighthappen,butIwasreallythinkingalongthelinesof20yearslaterandnotsix,''saidCornell.Wiemansaid:``IdiscoveredthatI'mnotnearlyasexcitedab