Oxide Materials for Electronic Engineering
Peter Y. Zavalij
X-ray Crystallography Center
Department of Chemistry and Bioch...
University of Maryland at College Park
Located North-East of Washington, DC:
only 15 miles from the White House
z
University of Maryland at College Park
http://www.umd.edu/
The University has:
26,000 undergraduate
11,000 graduate studen...
http://www.chem.umd.edu/
The Department is located in 6 buildings/wings and
has about 50 professors, 100+ graduate student...
X-ray Crystallographic Center
http://www.chem.umd.edu/facility/xray/
Single Crystal Diffraction
Chemical Crystallography
X...
Why Vanadium Oxides?
 Vanadium oxides and their intercalates present:
• Very rich chemistry because of wide range of
oxid...
Anode: pure Li, Li+Cgraphite, Li-Sn alloys
Cathode: Metal Oxide, Phosphate + Binder (teflon)
+ Conductor (carbon black)
El...
0 50 100 150 200 250 300
1.5
2.0
2.5
3.0
3.5
4.0PotentialinVolts
Capacity in mAh/g
(mAh/cm3
or mol(Li)/formula)
Discharge
...
0
1
2
3
4
5
0 0.2 0.4 0.6 0.8 1.0
x
Potential,Volts
x in LixSn
Potential,Volts
0 1 2 3
0
0.5
1.0
1.5
x in LixSn
Potential,...
Structural Relationship of Vanadyl Phosphates
in Electrochemical Cycling
ELECTROCHEMICAL
CYCLING
-H
ELECTROCHEMICAL
OR THE...
~tma(V2O5)6
tma(V2O5)4
LixV2O4
.
H2O
tmaV3O7
Li3VO4
2
4
6
8
10
pH
tma(V2O5)2
Coordination Polyhedra vs. pH in tma Intercal...
Coordination Polyhedra & Oxidation State
5+ 3+…5+ ... 4+
TB
Trigonal
Bipyramid
T
Tetrahedra
SP
Square
Pyramid
Od
Distorted...
Metamorphosis of V-O Frameworks
pH
T+T TB,
SP
SP
Od
Single
Chain
Double
Chain
Single
Layer
Double
Layer (δ)
3D
Framework
B...
“{UU}” {UD} {UUDD} “{ud}” {uudd} “{UuDd}”
≡{Z}
c d e fba
Square-Pyramids (SP) chains
{OO×OO}
≡ {X}
{OO|OO}
≡ {Q}
{OO} {o} {oo} {o/}≡{W}
Octahedral (O) chains
V-O Frameworks: SP class
Class
(CP type)
Sub-class
(block type)
Dimension
No. of
types
Description
1 UD 1D, 2D 3+2*
Layers...
Class
(CP type)
Sub-class
(block type)
Dimension
No. of
types
Description
4
U-T 2D 3
Separate SP and T
(/U./3.2T.), (U./T....
O class
Class
(CP type)
Sub-class
(block type)
Dimension
No. of
types
Description
7 Q 1D, 2D, 3D 5+1*
Corner and edge shar...
O+SP class
Class
(CP type)
Sub-class
(block type)
Dimension
No. of
types
Description
10 Q-UD 2D, 3D 7
Corner sharing Q and...
O+T class
Class
(CP type)
Sub-class
(block type)
Dimension
No. of
types
Description
12 O-T 1D, 2D 3+1*
Separate or corner ...
Stoichiometry & Dimensionality
- Cluster
- Extended
framework
Oxidation State and Composition
pH
(NH4)2V3O8 (RT)
295 K
Sp. gr. P4bm
a = 8.8997(5) Å
c = 5.5732(4) Å
V = 441.42(5) Å3
NH4
+
 NH4 disordered in two orientat...
(NH4)2V3O8 (LT) – 3+2 modulation
Incommensurate Modulation Vectors Green – main unit cell
(strong reflections)
Red – modul...
(NH4)2V3O8 – ADPs at RT & LT
LTRT
 The same small ADPs for both V atoms
 Displacement of terminal O (V=O) is smaller at ...
(NH4)2V3O8 - Rotation of Polyhedra
 Coordination polyhedra VO5 & VO4
cannot be rigid units
a
b
(NH4)2V3O8 - Rotation of Groups
 Circular motions of rigid units VO5 & V2O7
 Does not explain large ADP of bridging O in...
(NH4)2V3O8 - Rotation & Translation
 Circular motions of VO5
 BOTH circular motions of VO4 &
translational motions of V2...
tmaV4O10 at RT and LT
 Displacement in V4O10 layer practically identical at RT and LT
 tma is less ordered at RT (previo...
tmaV4O10 - RT
293 K
Sp. gr. Cmcm
a = 17.1059(4) Å
b = 6.6369(1) Å
c = 11.7287(2) Å
V= 1331.56(4) Å3
RF = 4.24%
 Disordere...
tmaV4O10 - LT
100 K
Sp. gr. Cmc21
a = 16.7313(10) Å
b = 6.5977(4) Å
c = 11.7586(7) Å
V= 1298.01(13) Å3
RF = 8.88%
 The sa...
tmaV4O10 (LT) super cell
different type of layer
 Green – Tetrahedra
 Red – Square Pyramids
Super Cell
Average
structure
10 µm
 Disordered tma and tea
 Misfit:
 Cell dimension – b ≈ 3.6 Å
 tma & tea size – at least 6 Å
Powder data:
tmaV8O2...
Layers from
BaV7
O16
Vanadium Oxide Nano-rolls – RnV7O16
10nm10nm
Nano-rolls
(SEM)
Nano-rolls
Model
Atomic Pair Distributi...
Property
Magnetism
Structure
Catalysis
Instead of Conclusion
Battery
Thank You!
Oxide Materials for Electronic Engineering
Abnormalities in Reciprocal Space
Crystal/Structure What can be seen in Reciprocal Space
Disordered classic None (single l...
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Vanadium Oxide Extended Frameworks: *Structural Chemistry & Applications

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Vanadium Oxide Extended Frameworks: *Structural Chemistry & Applications

  1. 1. Oxide Materials for Electronic Engineering Peter Y. Zavalij X-ray Crystallography Center Department of Chemistry and Biochemistry University of Maryland at College Park, Maryland, USA Vanadium Oxide Extended Frameworks: Structural Chemistry & Applications
  2. 2. University of Maryland at College Park Located North-East of Washington, DC: only 15 miles from the White House z
  3. 3. University of Maryland at College Park http://www.umd.edu/ The University has: 26,000 undergraduate 11,000 graduate students 13,000 employees of which 3,000 faculties
  4. 4. http://www.chem.umd.edu/ The Department is located in 6 buildings/wings and has about 50 professors, 100+ graduate students Chemistry & Biochemistry Bioscience Research building The Department of Chemistry and Biochemistry in the College of Chemical and Life Sciences at the University of Maryland is gaining momentum. Apply Here
  5. 5. X-ray Crystallographic Center http://www.chem.umd.edu/facility/xray/ Single Crystal Diffraction Chemical Crystallography X-ray Powder Diffraction Materials Characterization
  6. 6. Why Vanadium Oxides?  Vanadium oxides and their intercalates present: • Very rich chemistry because of wide range of oxidation states +5, +4, +3, … • Interesting crystal-chemistry – amazing frameworks due to variety of coordination polyherda: tetrahedra, pyramids, octahedra, etc.  And therefore exhibit important properties such as: • Red-Ox – used in Electrochemical application; • Magnetic – which are often unique; • Catalytic – used in oxidative catalysis. Outlines:  Application in Battery Materials  Chemistry & Structures  Extended Frameworks  Modulation and Disorder  Nano-materials
  7. 7. Anode: pure Li, Li+Cgraphite, Li-Sn alloys Cathode: Metal Oxide, Phosphate + Binder (teflon) + Conductor (carbon black) Electrolyte - organic solvent + Li salt: LiClO4, LiPF6, LiAsF6,…+ LiB(C2O4)2 Rechargeable Battery Materials  Red-Ox Reaction - wide range of oxidation states V: 5+…3+, Fe: 3+…2+, Mn: 4+…2+ vs. Co: 3½ +…3+  Open Frameworks - minimal structural changes during cycling  Electrochemical Properties - Performance: capacity, stability, safety Li+ Li+ Li+ Li+ Li+ Li+ Li+ Li+ Li+ Anode Cathode ElectrolyteElectrolyte Separator Current Electrons Discharge Li+ Li+ Li+ Li+ Li+ Li+ Li+ Li+ Li+ Li+Li+ Li+Li+ Li+Li+ Li+Li+ Li+Li+ Li+Li+ Li+Li+Li+ Li+Li+Li+ Li+Li+Li+ Anode Cathode ElectrolyteElectrolyte Separator Current Electrons Discharge Electrochemical Cell
  8. 8. 0 50 100 150 200 250 300 1.5 2.0 2.5 3.0 3.5 4.0PotentialinVolts Capacity in mAh/g (mAh/cm3 or mol(Li)/formula) Discharge Charge Capacity Capacity Fading Polarization Voltage Slope 0 50 100 150 200 250 300 1.5 2.0 2.5 3.0 3.5 4.0PotentialinVolts Capacity in mAh/g (mAh/cm3 or mol(Li)/formula) 0 50 100 150 200 250 300 1.5 2.0 2.5 3.0 3.5 4.0PotentialinVolts Capacity in mAh/g (mAh/cm3 or mol(Li)/formula) Discharge Charge Capacity Capacity Fading Polarization Voltage Slope Electrochemical Cycling
  9. 9. 0 1 2 3 4 5 0 0.2 0.4 0.6 0.8 1.0 x Potential,Volts x in LixSn Potential,Volts 0 1 2 3 0 0.5 1.0 1.5 x in LixSn Potential,Volts 0 1 2 3 0 0.5 1.0 1.5 0 1 2 3 0 0.5 1.0 1.5 0 1 2 30 1 2 3 0 0.5 1.0 1.5 0 0.5 1.0 1.5 Multiple Steps & Slopes: Solid Solution: LixMnOm (x≥0) Two Phase System: xLiMnOm + (1-x)MnOm (0≤x≤1) 0 1 2 3 4 0 1 2 3 Potential,Volts x Electrochemical Behavior Sn Li0.4Sn LiSn Li2.3Sn Li2.6Sn Li3.6Sn Capacity, mAh/g 0 50 100 150 200 2.1 2.5 2.9 3.3 3.7 Potential,Volts NH4V4O10 Li0.5NH4V4O10 Li1.0NH4V4O10 Li1.5NH4V4O10 Li3NH4V4O10
  10. 10. Structural Relationship of Vanadyl Phosphates in Electrochemical Cycling ELECTROCHEMICAL CYCLING -H ELECTROCHEMICAL OR THERMAL DEINTERCALATION +Li -Li α-LiVOPO4 tetrag. VOHyPO4 ε-VOPO4 -H VPO4·H2O ELECTROCHEMICAL CYCLING -H ELECTROCHEMICAL OR THERMAL DEINTERCALATION +Li -Li α-LiVOPO4 tetrag. VOHyPO4 ε-VOPO4 -H VPO4·H2O a b ca b c Parental β-VOPO4 Disordered I41/amd P1 - Pnma P21/n ε-VOPO4 C2/c Li1.6… in-plane tilt axial tilt in-plane tilt axial tilt unknown structure
  11. 11. ~tma(V2O5)6 tma(V2O5)4 LixV2O4 . H2O tmaV3O7 Li3VO4 2 4 6 8 10 pH tma(V2O5)2 Coordination Polyhedra vs. pH in tma Intercalates tma = [N(CH3)4]+
  12. 12. Coordination Polyhedra & Oxidation State 5+ 3+…5+ ... 4+ TB Trigonal Bipyramid T Tetrahedra SP Square Pyramid Od Distorted Octahedra Or Regular Octahedra Oxidation State
  13. 13. Metamorphosis of V-O Frameworks pH T+T TB, SP SP Od Single Chain Double Chain Single Layer Double Layer (δ) 3D Framework Basic Acidic VO3 VO2Composition O:V
  14. 14. “{UU}” {UD} {UUDD} “{ud}” {uudd} “{UuDd}” ≡{Z} c d e fba Square-Pyramids (SP) chains
  15. 15. {OO×OO} ≡ {X} {OO|OO} ≡ {Q} {OO} {o} {oo} {o/}≡{W} Octahedral (O) chains
  16. 16. V-O Frameworks: SP class Class (CP type) Sub-class (block type) Dimension No. of types Description 1 UD 1D, 2D 3+2* Layers & chains of corner sharing UD chains (2{UD}.), ({UD}.{DU}.), 2(2{UUDD}.), {UD}, {UUDD} 2 UD-pipes 1D, 3D 2 Tunnel structure from corner sharing UD chains {/{UD}./6}, [/{UD}../6] or [({UD}.{DU}.).{UD}.] SP 3 ude 2D 5+1* Layers of edge sharing SPs (ud)1 , (udue)-1 , (ududedudue)7 , {uudd} (uddue)3 , (uddueduude)8
  17. 17. Class (CP type) Sub-class (block type) Dimension No. of types Description 4 U-T 2D 3 Separate SP and T (/U./3.2T.), (U./T./4.), (U.<T.T>.) 5 UD-T 2D 5 UD blocks and T … α-(UD.2T..), β-(UD.2T..), γ-(UD.2T..), ({{<UUD>.}2:<T.T>}..2T.) SP+T 6 ZT 2D 6 Zigzag UuDd chain and T … … α-({UuDd}:2T.), …, β’-({UuDd}:2T.), …, β,β'-({UuDd}:2T.) SP+T class
  18. 18. O class Class (CP type) Sub-class (block type) Dimension No. of types Description 7 Q 1D, 2D, 3D 5+1* Corner and edge sharing quadruple chains {Q}, ({Q}.), ({Q}:):), (Q), [(Q).], [(Q):{OO}:]. 8 X 3D 2 Corner sharing crossed quadruple chains [({X})::], [({X})::{OO}:] O 9 o-oo 2D, 3D 5 Closest packed single and double o chains shared corners [{o}.], [{oo}.]1×2 , [{oo}.]2×2 , ({oo}.), ({oo}.{o}.)
  19. 19. O+SP class Class (CP type) Sub-class (block type) Dimension No. of types Description 10 Q-UD 2D, 3D 7 Corner sharing Q and UD chains β(QUD), δ’(QUD), [(QUD)|{UD}|], [*(.3{UD}*).2{Q}.] [(({Q}.).UD).] ≡[(QUD).], [(({H}:).UD).] [(QUD):(QUD).], [(QUD):(QUD).(QUD).] O+SP 11 O-UD 2D, 3D 2 Separate or corner sharing O and UD blocks or chains ({UDO}.), [.{<OO>:}.2{UU}*{O.}.{UD}*]
  20. 20. O+T class Class (CP type) Sub-class (block type) Dimension No. of types Description 12 O-T 1D, 2D 3+1* Separate or corner sharing O and T ({O.}.2T.), (O..<T.T>..), (O..{2T.}.) 13 W-T 2D, 3D 3 Wave-like O chains and T ({W}:T.), ({W}:2T.), (..U|{W}:T.), [(({W}.).T.).B|B.] O+T 14 oe-T 2D 1 Double sheet layer of edge sharing O with inserted T ((OoOee)2.T)
  21. 21. Stoichiometry & Dimensionality
  22. 22. - Cluster - Extended framework Oxidation State and Composition pH
  23. 23. (NH4)2V3O8 (RT) 295 K Sp. gr. P4bm a = 8.8997(5) Å c = 5.5732(4) Å V = 441.42(5) Å3 NH4 +  NH4 disordered in two orientations (blue & yellow)  Additional diffraction peaks at low temperature a b
  24. 24. (NH4)2V3O8 (LT) – 3+2 modulation Incommensurate Modulation Vectors Green – main unit cell (strong reflections) Red – modulation vectors 3+2 Superspace Group: P4bm(-αα½, αα½)0gg Lattice Centering: (0, 0, ½, ½, ½) a = 8.8792(4) Å c = 11.1108(6) Å = 2×cmain V = 875.98(8) Å3 α = 0.3095(1)
  25. 25. (NH4)2V3O8 – ADPs at RT & LT LTRT  The same small ADPs for both V atoms  Displacement of terminal O (V=O) is smaller at LT  Stronger anisotropy of bridging O atoms  O3 displacement (red ellipse) is greater at LT  O4 displacement in V2O7 (red arrows) is greater at LT  ADPs depict in-plane rotation of VO5 and VO4 a b Average structure
  26. 26. (NH4)2V3O8 - Rotation of Polyhedra  Coordination polyhedra VO5 & VO4 cannot be rigid units a b
  27. 27. (NH4)2V3O8 - Rotation of Groups  Circular motions of rigid units VO5 & V2O7  Does not explain large ADP of bridging O in V2O7  Symmetry changes a b ?
  28. 28. (NH4)2V3O8 - Rotation & Translation  Circular motions of VO5  BOTH circular motions of VO4 & translational motions of V2O7  Explains large ADP of bridging O in V2O7 a b
  29. 29. tmaV4O10 at RT and LT  Displacement in V4O10 layer practically identical at RT and LT  tma is less ordered at RT (previous slide)  Terminal (V=O) oxygen atoms are more modulated in bc plane, while rest V and O atoms are displaced perpendicularly to the layer c b RT LT c a Average structures
  30. 30. tmaV4O10 - RT 293 K Sp. gr. Cmcm a = 17.1059(4) Å b = 6.6369(1) Å c = 11.7287(2) Å V= 1331.56(4) Å3 RF = 4.24%  Disordered tma (in m2m position)  Initially refined in Cmc21 – missed satellites (green)  1D Incommensurate modulation: q = 0.404b* ≈ 2 /5b* 3+1 Superspace Group: Cmc21(0β0)s00, β = 1-q = 0.5956(1) c b c a q a* b* Average structure Diffraction pattern
  31. 31. tmaV4O10 - LT 100 K Sp. gr. Cmc21 a = 16.7313(10) Å b = 6.5977(4) Å c = 11.7586(7) Å V= 1298.01(13) Å3 RF = 8.88%  The same disorder as at RT - when refined in main cell  Can be refined as regular structure in super-cell: aS=a, bS=5b, cS=2c; VS=10V 2D Commensurate modulation: q1 = 1 /5b* q2 = 1 /2c* q2 b* c* q3 c a Average structure Diffraction pattern
  32. 32. tmaV4O10 (LT) super cell different type of layer  Green – Tetrahedra  Red – Square Pyramids Super Cell Average structure
  33. 33. 10 µm  Disordered tma and tea  Misfit:  Cell dimension – b ≈ 3.6 Å  tma & tea size – at least 6 Å Powder data: tmaV8O20 Sp. gr. C2/m a = 23.655(2) Å b = 3.5931(3) Å c = 6.3175(5) Å β= 103.060(4)° V = 523.05(8) Å3 Single crystal: (weak diffraction) teaV8O20 Sp. gr. C2/m a = 25.52(2) Å b = 3.569(2) Å c = 6.276(4) Å β = 98.91(1) ° V = 564.9(6) Å3 tma - [(CH3)4N] + tea - [(CH3CH2)4N]+ Composite Structures: tmaV8O20 & teaV8O20
  34. 34. Layers from BaV7 O16 Vanadium Oxide Nano-rolls – RnV7O16 10nm10nm Nano-rolls (SEM) Nano-rolls Model Atomic Pair Distribution Function Phys. Rev. B, 2004 R – dodecyl amine
  35. 35. Property Magnetism Structure Catalysis Instead of Conclusion Battery
  36. 36. Thank You! Oxide Materials for Electronic Engineering
  37. 37. Abnormalities in Reciprocal Space Crystal/Structure What can be seen in Reciprocal Space Disordered classic None (single lattice) OD single lattice + diffuse peaks Twinned merohedral single lattice (several lattices perfectly coinciding with each other) non-merohedral, split or co-crystal several lattices with common origin (related by rotation or reflection) Modulated incommensurate main lattice usually with stronger peaks and additional lattice(s) shifted from the origin commensurate strange reflections conditions, main lattice may have stronger peaks Composite incommensurate several main lattices and additional lattices shifted from origin commensurate strange reflections conditions; main lattices may have stronger peaks Quasicrystal absent 3D lattice, non-crystallographic symmetry, e.g. 5-fold axis

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