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4 Abstract anocomposites of nickel nanowires enveloped by polypyrrole or vice versa was synthesized. For preliminary experiments, nickel nanowires was electrochemically deposited into the nanopores of alumina memebranes. Polypyrrole nanotubes was also synthesized in the nanopores of alumina membranes through electrochemical polymerization method. The nickel nanotubes were fabricated by electrochemical deposition outside the wall of the polypyrrole nanotubes. The formation and structure of nanocomposites of polypyrroles and nickel were studied by scanning electron micrography, and transmission electron microscope. The relation of structural and magnetic properties of the nanocomposites were examined by using X-ray diffraction, electron paramagnetic resonance, and superconducting quantum interference device experiments.

5 Abstract Polypyrrole nickel ( )., Al 2 O 3 nano porous membrane. Polypyrrole Al 2 O 3 nano porous membrane. polypyrrole ( ) electrochemical deposition. TEM SEM PPy-i. XRD EPR, SQUID.

6 Contents Polypyrrole Polypyrrole Electrochemical Deposition Chronopotentiometry PPy PPy deposition i

7 3.1.4 PPy-i (Scanning Electron Microscopy) (Transmission Electron Microscopy) X (XRD) (EPR) (SQUID) SEM Alumina oxide Polypyrrole PPy-i EPR X TEM SQUID Bibliography 53 ii

8 List of Figures Polypyrrole (a) Polypyrrole benzenoid. (b) Polypyrrole quinoid. (c) Polaron. (d) Bipolaron Diaz Diaz Diaz Diaz (a). (b) deposition (a). (b) (SEM) TEM EPR iii

9 4.1 Polypyrrole SEM SEM PPy-i SEM (a) PPy-i SEM (b) EPR (a). (b)ppy-i PPy-i XRD XRD (a).(b) PPy-i TEM PPy-i hysteresis iv

10 Chapter 1 (ano Technology: T),, כ.,,,,. 1 (nm) nm 1 (=1000nm) כ nm כ. כ?, 1

11 .. כ. כ, DA,,.,,,,, /. high-density perpendicular magnetic recording [1]. template.,., magnetic antenna material [2]., polypyrrole hetero style double nanotube., TEM SEM PPy-i. XRD EPR, XPS, SQUID. 2

12 Chapter (polyacetylene) S/cm כ [3]. Si Si.,. p-, n-. 3

13 ., 0.1 % -, 6% % כ., SS., 0.1 6% כ. כ, Su-Schrieffer-eeger(SS) כ., כ. (polypyrrole)... 4

14 2.1.2 Polypyrrole polypyrrole (PPy), trans-polyaectylene. Kivelson polyacetylene (degenerate), transpolyacetlylene [6, 7]. Kuivalainen poly(p-phenylene) Kivelson., polaron. polaron. polaron, bipolaron. 2.2(a) PPy benzenoid. PPy 2.2(b) quinoid. Quinoid (unpaired spin) polaron. Polaron כ. 2.2(c) polaron,. (unparied electron). polaron PPy polaron bipolaron. Bipolaron 5

15 . ( 2.2(d)) 6

16 Figure 2.1:. 7

17 Figure 2.2: Polypyrrole (a) Polypyrrole benzenoid. (b) Polypyrrole quinoid. (c) Polaron. (d) Bipolaron. 8

18 2.2 Polypyrrole Polypyrrole. Diaz. Diaz [10]., Waltman Bargon Diaz [11, 12].. Scheme 1, scheme 2, scheme 3, scheme 4 polypyrrole (dimer). scheme 1 R R+ scheme 2., R+ R. R+, R+ (dimer). scheme 3 -, scheme 4 scheme 3 9

19 (dimer). scheme 5, scheme 6 scheme 4 (dimer) (trimer). (dimer). (dimer) (dimer) (dimer) (trimer). scheme 6. (trimer) 5-5 ( -position) 3-3 ( -position) -. (oligomer) -coupling (polymer) -coupling. polypyrrole XPS [13, 14, 15]. -coupling polypyrrole כ. scheme 7, scheme 8, scheme 9 (trimer) (polymer) scheme 10. (monomer), (dimer), (trimer),, scheme 8 10

20 (polymer). scheme 9 (polymer). free doping scheme 9 (pyrrole) 3-4.., π-type (EPR) [14]. -couping p. (monomer) כ כ. 11

21 -e -1 E pa O +. + Scheme Scheme Scheme Scheme 4 Figure 2.3: Diaz 1 12

22 -e -1 E pa Scheme Scheme 6 Figure 2.4: Diaz 2 13

23 e -1 E pa Scheme 7 * * n Scheme 8 Figure 2.5: Diaz 3 14

24 + A - n +. A - n Scheme 9 (n + 2) X X =, R, Ar np + X X n X + (2n +2) + +(2n+2+np)e - Scheme 10 Figure 2.6: Diaz 4 15

25 2.3 Electrochemical Deposition Chronopotentiometry, כ. כ כ,. כ כ. כ. כ 2. 1,.. S כ.. כ. כ, 16

26 .. 2.3(a), 2.4(b) , iso 4 + icl 2 p stabilizer 2 BO 3.[16, 17] Watt s bath[18] p4, iso 4 : icl 2 : 2 BO 3 27:4:4. Working. i 2+ +2e i (2.1). working PPy, PPy כ. 17

27 Figure 2.7:. (a). (b). 18

28 Chapter כ PPy π- PPy. pyrole (acetonitrile) (TBAPF 6 ) (magnetic stirrer) 30. pyrrole 0.5 M 0.1 M

29 Figure 3.1:. 20

30 & C 2 C 2 C 2 C 3 C 3 C 2 C 2 C 2 C 2 C 2 C 2 C 3 C 2 C 2 C 2 C 3! " & ( & ) + - / 1 Figure 3.2:. 21

31 3.1.2 PPy [4, 5]. Whatman alumina anodisc membrane ( :25, 47 mm, :60, pore size nm). (thermal evaporator) (Au) stainles steel membrane.,, stainless steel. (1 100 ma ) PPy [8]., pyrrole 10 ma

32 Figure 3.3: 23

33 3.1.3 deposition, alumina anodisc membrane i. membrane stainless steel Watt s bath i. Watt s bath iso 4 (300g/L), icl 2 (40g/L), 3 BO 3 (40g/L). cyclic voltammetry, chronopotentiometry PPy-i polypyrrole deposition [19, 20, 21, 22, 23, 24]. Polypyrrole stainless steel Watt s bath PPy-i. PPy pore.. deposition 3.4. (a), (b). PPy. cyclic voltammetry, chronopotentiometry. 24

34 Figure 3.4: deposition (a). (b). 25

35 3.2 (Scanning Electron Microscopy) 3.10 SEM. SEM kev., ( primary electrons) (secondary electrons), (Auger electrons) X-Ray. (CRT). SEM SEM CRT. CRT... PPy-i JEOL JSM-5200 (SEM). 26

36 Figure 3.5: (SEM). 27

37 3.3 (Transmission Electron Microscopy) (TEM) TEM, כ...,,, STEM, EDAX, line scanning mapping... TEM PPy-i membrane 28

38 ao PPy-i grid, כ JEM-2000EX. 29

39 !!! 222! """" #### $ $ $ $ &&&& '''' (((( )))) )))) (((( Figure 3.6: TEM. 30

40 3.4 X (XRD) X Bragg θ. nλ =2d sin θ (3.1), d. כ (2θ) Scherrer. (2θ) = λ L cos θ (3.2) L (coherence length) d L = d.,. PPy-i membrane 2M ao powder XRD. X Philips X PERT MPD. X source CuK α, λ =1.54Å

41 3.5 כ (EPR) Bruker ESP 300 EPR (spectrometer) X-band (9.5 Gz). EPR Console, (microwave bridge), (signal channel), (magnet), (cavity). (controller). 3-5 EPR. EPR,. 38,000 Gauss 39,000 Gauss (sweep),, Console EPR. (waveguide),.. (critical coupling) כ, (iris). (resonance),., כ Q (factor). Q [9], Q. Q = 2π(energy stored) dissipated energy per cycle (3.3) 32

42 Q.,. 33

43 Figure 3.7: EPR. 34

44 3.6 (SQUID) SQUID(Superconducting QUantum Interference Device, ). SQUID [T]. SQUID, hysteresis. ysteresis coersivity, remanence, saturation magnetization. SUQID MPMS5 SQUID Magnetometer. 35

45 Chapter SEM Alumina oxide i DC, AC, pulsed depositon. AC pulse alumina barrier layer. i. 1V, i.. 10mA, i. 3 alumina membrane 60 36

46 . 10 ma 40, i PPy. 0 2M ao alumina oxide PPy-i. SEM Polypyrrole כ Polypyrrole pyrrole TBAPF 6 5: nm 200 nm. 25 5mA, 2.1V 2.5 V

47 Figure 4.1: Polypyrrole SEM. 38

48 4.1.3 כ,. 100 nm membrane. 10mA. 4.2 SEM PPy-i כ PPy, Watt s bath, 10mA 40 PPy-i

49 Figure 4.2: SEM. 40

50 Figure 4.3: PPy-i SEM (a). 41

51 Figure 4.4: PPy-i SEM (b). 42

52 4.2 EPR PPy-i EPR, PPy-i כ. 4.5 כ. EPR, Dysonian Line-Shape asymmetry form כ. PPy-i Polypyrrole, symmetry form כ. 43

53 dp/d (Arb.Unit) Magnetic Field (Gauss) dp/d (Arb.Unit) Magnetic Field (Gauss) Figure 4.5: EPR (a). (b)ppy-i. 44

54 4.3 X X PPy-i. Membrane PPy-i ao. 4.5 כ.. כ. XRD 4.7. כ Membrane. bulk. 45

55 Intensity (Arb.Units) Au i (111) Au i (200) Au Au i (220) i (311) θ Figure 4.6: PPy-i XRD. 46

56 400 Intensity (Arb.Units) θ 1000 Intensity (Arb.Units) i (111) i (200) i (220) i (311) θ Figure 4.7: XRD (a).(b). 47

57 4.4 TEM 4.8 PPy-i TEM. 40 PPy-i. TEM, PPy. etero style double nanotube כ. 48

58 Figure 4.8: PPy-i TEM. 49

59 4.5 SQUID 4.8 PPy-i hysteresis... Remanence saturation magnetization hysteresis M/M s. Coercivity 65 gauss. coercivity. gauss coercivity.. 50

60 M/M s Magnetic Field (gauss) Figure 4.9: PPy-i hysteresis. 51

61 Chapter 5 Al 2 O 3 π- polypyrrole., PPy. EPR, XRD, XPS. SEM, TEM PPy-i., SQUID PPy-i. 52

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