NIMSAWARD2025-abstracts

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P1-1350Development of Atomic-Resolution Liquid Cell Transmission Electron MicroscopyEnvironment-Controlled Microscopy Group, GREEN Masaki TakeguchiE-mail：： TAKEGUCHI.Masaki@nims.go.jpKey Words: Liquid Cell, STEM, Atomic-ResolutionLiquidcelltransmissionelectronmicroscopy(LCTEM)isatechniqueforobservingsamplesintheliquidphase.Itenablesimagingofnotonlysamplestructuresbutalsochemicalreactionswithhighspatialresolution.However,LCchipwindows (SiNx)andliquiddegraderesolution.Severalchallengesremaininconsistentlyachievinghighspatialresolution,whichhaslimitedthewidespreadadoptionofLCTEM.Wehaveinvestigatedmethodologiestoimprovespatialresolutioninthistechnique.Electronchannelingalongtheatomiccolumnsenabledatomic-resolutionLC-STEMimagingwithhighcontrast.Thishigh-contrastimagingcanlowertheprobecurrentandisexpectedtomitigateelectron-beam-inducedradiolysisandminimizeundesiredsampledamage,particularlyunderhigh-magnificationimagingconditions.ConclusionSamplesusedwereSrTiO3<001>lamellaspreparedwithafocusedionbeam(FIB)technique.Thethinnedregionwaslessthan100nminthickness.TheFIB-preparedSrTiO3<100>lamellaswerepicked-upandputontoachipwindowatthedesiredpositionusingaglassprobeandanopticalmicroscopeinair to avoid Ga ion irradiation induced damageofthewindowduringthetransferprocess(Fig.1).Thechipwassetinadouble-tiltLCvessel,andapurewaterdropletof0.1µLwasdroppedontoit,followedbycoveringanotherchip.Finally,itwasfixedbyalidandscrewstocompletetheassemblyoftheLCholder(Fig.2).FIB sample setting in a double-tilt LCSTEM imaging Thistechniquewillfacilitateatomisticobservationsofreactionsatsolid-liquidinterfaces.Weplantodevelopadouble-tiltelectrochemicalLCholder.Future PlanFig.3(a)showsanannulardarkfield(ADF)STEMimageofthesampleintheLC,takenwithanaberration-correctedSTEMinstrument,JEM-ARM200F.Oxygensignalsfromtheareaapartfromthesampleinelectronenergylossspectroscopy(EELS)confirmedthatawaterlayerexistedthere.Fig.3(b)showsanatomic-resolutionADF-STEMimagefromathinarea,acquiredafteraligningthesampleorientationalongthe<100>zoneaxis.SrandTi-Oatomiccolumnscanbeclearlyseen.TheSNRofSrcolumnswascalculatedtobe4.5.Thewaterthicknesswasevaluatedtobeapproximately80nmusingtheEELSlog-ratiomethod(Fig.3(c,d)).Thus,itwasdemonstratedthatelectronchannelingalongseveraltensnmatomiccolumnsresultedinhigh-contrastatomicimagesovercomingbackgroundfromchipwindowsandliquid.IntroductionOneprimaryfactorcontributingtoresolutiondegradationisthereducedsignal-to-noiseratio(SNR)ofsamplesrelativetothebackground,largelyduetotheLCchipwindowsandthepresenceofliquid.Toaddressthis,wehavedevelopedadouble-tiltLCholderthatenablesobservationofsinglecrystalsamplesunderzoneaxisincidenceconditions,therebyenhancingthecontrastofatomiccolumns(improvingtheSNR).Theme underDiscussion10 µm(c)(d)WindowGlass Probe(b)(a)5 µmReservoirGasket grooveSpacerFig.1 (a) FIB-prepared SrTiO3<100> sample, (b) Sample pick-up using a glass probe, (c) Top-view of a liquid cell chip with an on-chip fluidic chamber, and (d) Sample on a chip window.b)a)Y-tilting rodL-shape transmission deviceLC holderHolder bodySi chipsY-tilting axis pinSpringFig.2(a)Schematicofthecross-sectionand(b)photoofthedevelopeddouble-tiltLCholder.Fig.3 (a) Low-mag and (b) high-mag ADF-STEM images of FIB-prepared SrTiO3<100> sample. (c)(d) EEL spectra taken from the sample with and without water.-250255075100125150175200t/λ=2.54(d)SrTiO3+two SiNxEnergy (eV)-250255075100125150175200t/λ=2.82(c)Water+SrTiO3+two SiNxEnergy (eV)Water conditionDry condition