简介:Moleculardynamics(MD)simulationswereperformedtostretchtherectangulargraphenesheetsdopedwithsilicon,nitrogenorboronatoms.Young’smodulus,ultimatestress(strain)andenergyabsorptionweremeasuredforthegraphenesheetswiththedopingconcentration(DC)rangingfrom0to5%.Theemphasiswasplacedonthedistincteffectsofeachindividualdopantonthefundamentalmechanicalpropertiesofgraphene.TheresultsindicatedthatincorporatingthedopantsintographeneledtoanalmostlineardecreaseinYoung’smodulus.Monotonicreductionsinultimatestrength,ultimatestrainandenergyabsorptionwerealsoobserved.Suchdopingeffectswerefoundtobemostsignificantforsilicon,lesspronouncedforboron,andsmallornegligiblefornitrogen.Theoutputsprovideanimportantguidanceforthedevelopmentandoptimizationofnovelnanoscaledevices,andfacilitatethedevelopmentofgraphene-basedM/NEMS.
简介:Inthepaper,thenonlinearmagnetoelasticpropertiesofcompositionTb0.27Dy0.73Fe1.95<110>orientedpolycrystallinealloysareinvestigatedundercoupledloadsofhighmagneticfieldandcompressivestress.Themagnetizationandmagnetostrictionaremeasuredsimultaneouslyunderappliedmagneticfieldfrom800to800kA/mandcompressivestressfrom0to25MPaatroomtemperature.Thestraincoefcientandrelativepermeabilityareobtainedbydiferentialcalculationfromtheexperimentalcurves.Theresultsshowthatthevaluesofsaturationmagnetization(Ms)underdiferentcompressivestressesremaininvariablyconstantintheregionofthehighmagneticfield.Thesaturationmagnetostriction(λs)increaseswithincreasingcompressivestressandreaches1680×106under25MPa.Accordingtotheincreaseofthecompressivestress,thehystereticloopareaofmagnetizationandmagnetostrictionincreases,whilethemaximumrelativepermeabilityandstraincoefcientdecrease.Additionally,theinfluenceofthebiasmagneticfieldonthemechanicalpropertyistakenintoaccount.Thestress-strainrelationshipisnonlinearandsensitivetotheappliedexternalmagneticfieldsalongtheaxisofrod.Theresultsobtainedareausefulcomplementtotheexistingexperimentsfortheoreticalapproachesandengineeringapplications.