文档介绍：AtomicAtomic forceforce microscopemicroscope (AFM)(AFM)
JayJay . TangTang
AssistantAssistant ProfessorProfessor ofof PhysicsPhysics andand
Engineering,Engineering, BrownBrown UniversityUniversity
Facility funded by a National Science Foundation Major
Research Instrumentation Award, NSF DMR 0320676
AcquisitionAcquisition ofof aa ScanningScanning ProbeProbe MicroscopeMicroscope forfor StudiesStudies
ofof BiomaterialsBiomaterials andand NanoscaleNanoscale MaterialsMaterials andand DevicesDevices
Principle Investigators:
Jay X. Tang, Gang Xiao, James M. Valles,
Thomas R. Powers, and Sean Ling
Facility Manager: Dr. Guanglai Li
Contact Information:
Jay_******@
Guanglai_******@
OutlineOutline
•• WhatWhat isis anan AFM?AFM?
•• WhatWhat cancan itit do?do?
•• WhatWhat areare thethe ponents
•• ModesModes ofof operationoperation
•• RepresentativeRepresentative images,images, goodgood andand
fakefake
WhatWhat isis anan AtomicAtomic forceforce microscope?microscope?
AtomicAtomic forceforce microscopemicroscope (AFM)(AFM) isis aa postpost--childchild ofof
ScanningScanning ProbeProbe MicroscopeMicroscope (SPM),(SPM),
whichwhich isis aa postpost--childchild ofof
ScanningScanning TunnelingTunneling MicroscopeMicroscope (STM)(STM)
STMSTM waswas inventedinvented inin 1981,1981, byby GerdGerd BinnigBinnig andand
HeinrichHeinrich RohrerRohrer atat IBMIBM ZurichZurich
PhysicsPhysics BehindBehind STMSTM
••Tunneling effect:
– Conduction of electrons through a narrow gap (10 Å)
(Note: 1 Angtrom = nm =10-10 meter
Recall: m->mm->μm->nm, shrinking by 1000)
– This is a quantum mechanical effect!
•• Main features:
– rapid drop when distance increases
– sensitive to bias voltage
AFMAFM Tip:Tip: CantileverCantilever andand TipTip
HowHow doesdoes anan AFMAFM looklook like?like?
AFMAFM scanningscanning andand detectiondetection
TwoTwo modesmodes ofof operationoperation
•• Contact Mode
– keep the deflecti