364 , , : , , , , , , . , , , .
:
364150
(304)
(123)
(23)
(113)
(4)
(4814)
(5227)
(2616)
(3423)
(4214)
(1518)
(68)
- (2836)
(8269)
(50)
(50)
(762)
(2)
(5275)
(30)
(1222)
(43)
(20403)
(465)
(19)
(108)
(173)
(96)
(899)
(54)
(34)
(476)
(106)
(62792)
(3562)
, (6444)
(2165)
(21320)
(766)
(64)
(3145)
(60)
(17)
(588)
(1000)
(106)
(48)
(3)
(1167)
(8485)
(537)
: (2044)
(11657)
(532)
(21)
(7985)
(3721)
, (10549)
(88)
(58)
(36)
(2257)
(12491)
(91)
(797)
(1338)
(24)
, (214)
(1141)
(3)
(8)
(21697)
(7850)
(3801)
(682)
, (2881)
(475)
(1)
, (7100)
(8694)
, (4121)
(443)
(952)
(2967)
(23)
(748)
(4876)
(95)
(107)
(7)
(2004)
(15)
(663)
(240)
(39)
(25)
(624)
(16)
(2652)
(136)
(90)
(406)
(95)
(24)
(3463)
(4482)
(7216)
(4592)
(5386)
(3)
(2244)
(23)
(29)
(35)
(4517)
(20645)
- (666)
(119)
(2573)
(889)
(288)
(148)
, (1140)

: Application of angstorm level resolution in nanotechnology

: Application of angstorm level resolution in nanotechnology
:
: 13:55:41 29 2010
: 15 : 3 : 0 : 0 :    

Applctns f ngstrm Lvl Rslutn n Nn Tchnlgy


1. ntrductn

Lkng bck, th bgnnngs f mcrscpy dt bck t th tm f Rbrt Hk whr h usd pc f glss lns fr mgnfy f hs spcmn by bndng th ry f lght. t ws vn prt f hs bk Mcrgrph nd th frst ptcl mcrscp ws dvlpd. Th dvlpmnt f th hgh pwrd mcrscps ws du t mns nd t furthr mgnfy nd s wht ur nkd y cn prcv. Mgnfyng n bjct s lmtd t bng bl t dstngush n pnt frm th thr, smpl dfntn f rslutn. Th dstnc f tw pnts f whch bng sprt dstnct ntts s th lmt f rslutn [1]. Th dvlpmnt ws bsd n th xhustd ptntl f th tls. Hstrclly, th prblms wth rslutn s wll s mn functn f th tl wr th mn fctr fr th dvlpmnt f nw mcrscp. Rslutn hd bn th frmst cncrn fr th dvlpmnt f th hgh pwrd mcrscp up t th lctrn mcrscp lvl. Th ptcl mcrscp srvd s th mdl fr th dsgn nd cncpt f th succdng mcrscps. Th wv ntur f lght ws th mn bckbn f rslutn s t s rltd t wvlngth by th bbs qutn [1]:

Application of angstorm level resolution in nanotechnologyqutn 1 [1]

whr d = rslutn

λ = wvlngth f th nrgy surc

n = ndx f rfrctn f th mdum thrugh th nrgy surc trvls

ά = prtur ngl

Gvn ths rltnshp f lght wv nd rslutn, thr surc f llumntn r nrgy ws drvd. Th lctrn mcrscp ws dvlpd usng lctrns cclrtng n th spd f lght [2]. Thy usd lctrns frm sturtd bm t g thrugh lctrmgntc lnss bng bl t rslv ngstrm thck f mtrl [1,2]. Th lctrmgntc lnss srvd t dflct th lctrns thrugh th clumn. Ths cpblty f th lctrn mcrscps md t pssbl t rslv frm th mcrn lvl (thusndth f mtr), nn lvl (mllnth f mtr) t sub ngstrm (lss thn tn mllnth f mtr). Thugh hgh mgnfctns cn b chvd, th M ws lmtd by brrtns du th wv dflctd n th lnss [2]. Tdy, ctupls nd qudrupls r ddd cmpnst fr th sphrcl brrtns. nthr lmttn f lctrn mcrscps, chrmtc brrtn, s bng rslvd wth th TM (Trnsmssn lctrn- brrtn crrctd Mcrscp) prjct f th ntnl lctrn mcrscpy lbs hr n th US. Th hghst rslutn n n lctrn mcrscp tdy s t 0.7 ngstrm.

Mcrscpy plys bg rl n th nntchnlgy rvlutn. ccrdng t M [3], th cntrl chllng n nntchnlgy s dntfctn f nn mtrl synthss nd undrstndng structurs n nn r sub nn mtr lvl. Th mcrscpy tchnqus nbl scntsts t lk nt th structurs s t shp, sz, structur nd rnttn f nn mtrls [3]. Lrnng vsully s ky t bttr undrstndng t nw tchnlgy such s ths. Spcfc pplctns f nn mtrl chrctrztn by mcrscpy wll b dscussd furthr n th ppr.


2. Lmttns f lctrn Mcrscps

lthugh hgh mgnfctns wr chvd n th lctrn mcrscps, blurrnss ccurrd. Ths ws du t th wvs tht wr dflctd s th lctrns trvl dwn th clumn [1,2,4]. Ths wvs wr clld brrtns, sphrcl nd chrmtc brrtn. Th lctrn mcrscp dvlpd n th 16th cntury. n tht tm prd nd ftr, dffrnt typs f lctrn mcrscps wr dvlpd bsd n th dffrnt pplctns. Ths wr th SM (Scnnng lctrn Mcrscp), STM(Scnnng Tunnlng Mcrscp), SPM (Scnnng Prb Mcrscp) nd FM (tmc Frc Mcrscp). Thr ws pnt tht dvlpmnt ws stgnnt. By 1998, th dvlpmnt f brrtn crrctrs ws studd. Th push t dvlp n brrtn fr lctrn mcrscp hd bn ngng snc thn. Th ntnl lctrn mcrscpy lbrtrs n th US r wrkng t slv ths hndrnc n mcrscpy. Nllst [4] numrtd th ky vnts rgrdng brrtn snc th bgnnng f mcrscpy:

Th 10 ky momentsn th pth t tmc rslutn [4]:

16th cntury Th dvlpmnt f th cmpund ptcl mcrscp
1873 rnst bb prsnts dtld thry f mg frmtn n th mcrscp
1896 Lrd Rylgh dfns th rslutn lmt fr n ptcl systm by cnsdrng dffrctn f wvs n th lns prtur
1933 Knll nd Rusk nvnt th trnsmssn lctrn mcrscp
1936 tt Schrzr shws tht lctrn lnss r lmtd by ntrnsc sphrcl brrtn
1955 rwn Müllr uss fld n mcrscp t btn th frst mgs f tms
1970 mgs f sngl thllum tms chvd by lbrt Crw nd c-wrkrs usng STM
1970s Rslvng crystl lttcs usng trnsmssn lctrn mcrscp strts t bcm rutn
1982 Bnng nd Rhrr nvnt th STM, whch s cpbl f mgng tms n surfcs; thr scnnng prb mcrscps fllw
1998 nwrds Th dvlpmnt f sphrcl-brrtn-crrctn tchnlgy strts t rvlutnz TM prfrmnc nd brngs but rutn sub-ångström-rslutn mgng

Th d Brgl wvlngth prncpl ( wvlngth s qul t Plnks cnstnt dvdd by mmntum; l = h / p) ds nt nswr th prblm f brrtn. Th lmttn by brrtns ws dcttd ccrdng t Rylgh by dffrctn [4,5]. Nllst xplnd by th qutn[4]:

d= 1.22 λ/θ qutn 2 [4]

whr d = rslvng pwr, λ= wvlngth nd θ = ngl subtndd by th prtur.

Bsd n qutn 2, th M wll rqur prfct lns. Th fcl lngth f n M lns s 2mm, t thn rqurs wvfrnt t b fcusd n prcs dstnc f n qurtr f wvlngth, rund 5 pcmtrs [4]. Ths prfct lns cnnt b prducd wth lctrmgntc lnss f n M. Unlk rgulr glss lns t cn b prfctd by plshng r grndng, lctrmgntc lnss cn nly b cntrl by th prncpl f Mxwll rltns [4]. s xplnd by Βkf [5], ncrsng th cclrtng vltg mprvs rslutn by rducng th lctrn wvlngth by 12 th squr rt f th wvlngth. chvng th ngstrm rslutn wuld stll rqur crrctrs t dcrs brrtns.

Th crrctn tchnlgy s nw vlbl fr th TMs.Th prsnc f ctupls nd qudrpuls dflcts th bm twrds n ptc xs such n Fgur 1.

Th ctupls r ght ltrntng pls f pstv nd ngtv tht dflct th bm hwvr nthr qudrupl-ctupl s rqurd. Ths crrctr srvs t frm "ln crss vr" pnt tht ll th wvs cnvrgs nd thn fnlly gs thrugh th qudrupl t th fcl pln [4,5]. s mntnd n th ppr f Nllst [4], t s mprtnt t hv ll th pls prprly ln up snc t cn stll cus sphrcl brrtn. Th pplctn f ths crrctrs s dpndnt n th vltg th M. chvng sub ngstrm lvl rslutn wuld stll rqur md vltg prtn t rduc th wvlngth [5].


Application of angstorm level resolution in nanotechnology

Fgur 1. s th bm gs thrugh th prtur, sm rys r dflctd cusng sphrcl brrtn, (mddl) ctupl ddd t th bm but nt nugh t hv n crssvr s t psss thrugh th crrctr. Ths cn b crrctd by ddng qudrupl (bttm) tht frms ln crss vr thn dwn brrtn fr t th qudrupl-ctupl bfr t furthr trvl t th fcus pnt [4].

pplctns f Mcrscpy n Chrctrztn f Nn Mtrls

Nntchnlgy rvlvs n buldng nw mtrls n tmc lvl [7]. Strtng frm th rw mtrl, t vntully prcssd nd thn chrctrzd. Thrugh th chrctrztn prcss, th prprts f th nw mtrl s studd nd thn dvlpd fr pplctns. ur scty s mvng twrds ths nw r nd bttr tls r ndd t chrctrz th nw nn mtrl w r buldng. s mntnd n th ntrductn, mcrscpy n nntchnlgy chrctrztn s nvtbl.

s n xmpl, S/TM r TM cn prvd th sz, shp structur, nd rnttn f nn crystls nd nn wrs [3]. Wth th mgs btnd frm studs, mr nfrmtn ws btnd but th nn mtrl spclly rgrdng synthszng th sd mtrl. n stu studs usng th TM r dvlpng wth prbbl cnvrgnc f mcrscpy wth cmputtnl mtrl studs [8].

Mcrscpy s utlzd fr plymr nncmpsts fr rspc chrctrztn s wll. t th mlculr lvl, th us f SM, TM, HRTM nd FM, prvds th physcl nd chmcl prprts f nntubs tht wuld b bnfcl fr wll usd plymtrc mtrl [9]. Ths mthd ws dfnd t b mcrmchncl mdlng tht wuld prdct th bhvr f th cmpst rnfrcd wth fbrs lrgr thn th nnmtrl. n study by Njugun t.l. [9 ], thy dscussd th rl f mcrscpy tchnqus fr chrctrztn f plymr nncmpsts. Summry fllws [9]:

FM gd mgng cn b btnd n dffrnt nvrnmnt f th smpl such s n lqud, vcuum r lt tmprturs.

TM tmc rslutns ttnbl wth cpblty f cllctng lctrn nrgy lss spctr t mp chrctrstc x-ry mssn spctr.

HRTM mg rcnstructn nd rstrtn tht prvd sptl rslutn t mprv th lvl fr quntttv dt ntrprttn.

Rmn Spctrscpy mprtnt n surfc rctns.

Just lk th FM, th SPM hs mjr rl n chrctrztn nd fbrctn s wll f hybrd nn mtrls. n th study by Hrsm t. l. [10], thy hghlghtd th dvlpmnts n SPM tchnqus tht prvdd nfrmtn n structur nd prprts f hybrd nnmtrls. Th tchnqus mntnd n th study wr tw-dmnsnl sptl mppng f mchncl prprts, n dmnsnl frc spctrscpy whch s usully utlzd fr blgcl hybrd nnmtrls; nd fnlly cnductv FM chrctrztn fr rgnc smcnductrs, blgcl smpls, slf ssmbld mnlyrs, nncmpsts tc. [10]. SPM cn ls b usd n fbrctn by th lthgrphy tchnqus. Thy suggstd mprvmnts n th nlytcl nd xprmntl prcdurs fr bttr chrctrztn f nn mtrls [10].

Tdy wth th crrctrs t slv th brrtns n th M, th sub ngstrm rslutn mcrscp s vlbl. Thus, vsulztn t th nn lvl nd chrctrztn s much sr. Th frst ngstrm lvl M ws prducd n Lwrnc Brkly Ntnl Lbrtry. M (n-ngstrm Mcrscp) ws mdfd FŲ TM wth hrdwr nd sftwr crrctrs tht rducd th sphrcl brrtns dscussd rlr [5]. sd frm ths prgrms, furthr dvlpmnt ws dn by ddng th crrctrs n th TM. FŲ cmpny cm ut wth Ttn, S/TM wth rslvng pwr f 0.7 ngstrm t 80-300 kv [11]. Ths lctrn mcrscp s nw vlbl n th mrkt hwvr thr r nt lt f studs bng dn usng ths mcrscp yt.

Ttn s frsn t b usd n chrctrztn f lctrncs prprts thrugh bnd gp studs nd ls wll b gd tl n studyng cmputtnl mdls [11]. Fr th sm rsn, n f ths mcrscps ws dntd t th h Stts, Cntr fr cclrtd Mturtn f Mtrls (CMM). Wth th brrtn crrctd fr n M, th mpct n chrctrztn s nw grtr. Usng th Ttn, th dfcts nd ts structur cn nw b vsulzd wth th tmc clumn clrly mgd. Vsblty f ndvdul tms r nw clrr nd nt just prjctns. ls, thr dmnsnl nfrmtn my b vlbl f th M s dsgnd t hv wdr bms n th mn mgng lns [4,11].

Th TM prjct nd th futur f mcrscpy

Th dvlpmnt f mcrscpy dclnd wth th slutn fr brrtn lft hngng. Frm th dvlpmnt f ptcl mcrscp up t tht f th lctrn mcrscps, th lmttn n rslutn ws ttnd thus lvng th prvus n lmst bslt. Th futur f lctrn mcrscp wll stll g lng wy wth TM prjct. Dffrnt ntnl lbrtrs r wrkng t slv brrtns n M. Thy nmd thr prjct s TM (Trnsmssn lctrn- brrtn crrctd Mcrscp). ccrdng t Brwn [6]:

"n f th gls s t chv rslutn f 0.5 Ångstrm rslutn but n-mlln tms smllr thn th dmtr f humn hr by th nd f th dcd, nthr bjctv s t cqur thr-dmnsnl mgs t tmc rslutn. Tdy's bst mcrscps cn nly mg tw-dmnsnl prjctn f clumns f tms [6]."

Thr r fv lbrtrs tht r undr ths prjct nmly: rgnn Ntnl Lb, Brkhvn Ntnl Lb, Lwrnc Brkly Ntnl Lb, k Rdg Ntnl Lb nd Frdrck Stz Mtrls Rsrch Lb. ch lb hs ts wn tsk n th prjct. rgnn Ntnl Lb s rspnsbl fr buldng 13 lnss fr th "Ultr" crrctr whl th thrs wll mprv th dtctrs mgng nd nlyss, bm sz nd currnt, tls fr xprmntl purpss n th mcrscp nd sftwr fr rmt cntrl nd dt hndlng [6]. n stu xprmnts r xpctd t b tstd n ths M nd mr xprmntl spc wll b dsgnd s wll [6].

Application of angstorm level resolution in nanotechnologyApplication of angstorm level resolution in nanotechnology

Fgur 2. DMND VW Ths vws f dmnds shw th dffrnc th TM mcrscp wll mk. Th lft mg shws th bst mg pssbl tdy. Th rght mg smults wht wll b vsbl wth th brrtn-crrctd mcrscp [6].

Th futur f mcrscpy wll nt nd by th nd f ths dcd. vn thugh sphrcl brrtn s rslvd, chrmtc brrtn hndrs th gl chvng th ultmt brrtn fr lctrn mcrscp. Chrmtc brrtn ccurs whn th wvlngths cnt cnvrg nd t b fcusd t th sm tm [2,4]. Th cndtns f hghr nrgy f wvlngths prsnt n th TM mk t dffcult t slv ths typ f brrtn. Mr wvlngths r xpctd n trnsmssn md cmprd t th SM snc t rqurs hghr bm nrgs [4]. Thus, nw lctrn gun r surc wll b dvlpd [4]. Ths dvlpmnt s lkd nt by th cmpny Nn.


3. Cnclusns

Th crrctrs fr sphrcl brrtns ndd mprvd th rslvng pwr f lctrn mcrscps s shwn by th cpblts f th FŲs Ttn. Th rl f mcrscpy n chrctrztn f nnmtrls s vry mprtnt wth th dffrnt studs rvwd tht utlzd such tchnqu nd tls. Wth th TM prjct f th ntnl lctrn mcrscpy lbs, mr mprvmnts nd nnvtns r xpctd n th futur nt nly n th qupmnt but th mthds f studs s wll.


Rfrncs

1. M.T. Pstk, K.S. Hwrd, .H. Jhnsn, nd K.L. McMchl, Scnnng lctrn Mcrscpy, ( Ldd Rsrch ndustrs. Wllstn, Vrmnt, 1980), pp. 1-11.

2. J.J Bzzl nd L.D Russll, lctrn Mcrscpy: Prncpls nd Tchnqus fr Blgsts , 2nd dtn, (Jns nd Brltt Publshrs, Sudbury, Msschustts, U.S.., 1999), pp. 1-17

3. C. M, "Nnmtrls Chrctrztn Usng Mcrscpy", Mcrscpy Rsrch nd Tchnqu, 64, pp. 345-346, (2004).

4. Nllst,P., (2005) Sng wth lctrns [nln] vlbl t http://nntchwb.rg/rtcls/ftur/4/11/1/1/PWl4%5F11%2D05 (ccssd Fbrury 13, 2006..

5. ΒKf, M.. (2004). Sub ngstrm Rslutn wth brrtn Crrctd TM: Prsnt nd th Futur [nln] vlbl t http://rpstrs.cdlb.rg/cg/vwcntnt.cg?rtcl=2640&cntxt=lbnl (ccssd Fbrury 13, 2006).

6. . Brwn, (2004) TM dsgns wrld's hghst rslutn mcrscp [nln] vlbl t http://www.nl.gv/Md_Cntr/Nws/2004/MSD041112.html (ccssd Fbrury 13, 2004).

7. Z. Gu, Sn Js Stt Unvrsty, pplctns f Nn Mtrls, lctur (Jnury 2006.

8. .M. Mnr, Nnmchncs-Usng n stu TM t undrstnd smll vlum dfrmtn. Lctur, ( Mrch 2006).

9. j. Njugn nd K. Plchwsk, "Plymr Nncmpsts fr rspc pplctns: Chrctrztn" , dvnc ngnrng Mtrls, 6, pp. 204-209, (2004).

10. M.C. Hrsm, M. Grn, C.R. Knsr, D.. Krmr nd L.S.C. Pngr, "pplctn f Scnnng Prb Mcrscpy t th Chrctrztn nd Fbrctn f Hybrd Nnmtrls", Mcrscpy Rsrch nd Tchnqu, 64, pp. 415-434, (2004).

11. FŲ Cmpny: FŲ Ttn TM [nln] vlbl t http://www.f.cm/systms/prduct.spx?d=231&rldd=tru (ccssd Fbrury 12, 2004).

/
:
? : letsdoit777.blogspot.com
06:48:15 19 2016
? : letsdoit777.blogspot.com
22:35:02 18 2016
9000 " "? : business1777.blogspot.com ! C !
13:16:26 25 2015

, : Application of angstorm level resolution in nanotechnology



, ?

, .
, .
, .
, .
, .



(150531)
(1836)
Copyright 2005-2016 BestReferat.ru bestreferat@mail.ru

@Mail.ru