Table 5 Structure parameters derived from the fitting of Fe K-edge EXAFS spectra of hematite and Al-doped hematite samples.

From: Mechanisms on the morphology variation of hematite crystals by Al substitution: The modification of Fe and O reticular densities

 

Hem

AlH1

AlH3

AlH5

AlH7

AlH9

AlH11

AlH13

Fe-O1 (1)

 CN

3

3

3

3

3

3

3

3

 R (Å)

1.933 (15)

1.942 (17)

1.939 (10)

1.939 (11)

1.942 (12)

1.939 (12)

1.937 (11)

1.938 (12)

 σ2 (Å)

0.0047 (15)

0.0052 (18)

0.0036 (8)

0.0036 (9)

0.0037 (11)

0.0034 (10)

0.0038 (9)

0.0036 (9)

Fe-O1 (2)

 CN

3

3

3

3

3

3

3

3

 R (Å)

2.078 (21)

2.076 (27)

2.090 (17)

2.088 (19)

2.089 (22)

2.089 (21)

2.087 (18)

2.093 (21)

 σ2 (Å)

0.0064 (24)

0.0087 (43)

0.0066 (18)

0.0069 (9)

0.0072 (25)

0.0067 (22)

0.0063 (17)

0.0068 (19)

Fe-FeF

 CN

1

1

1

1

1

1

1

1

 R (Å)

2.854 (35)

2.855 (32)

2.876 (29)

2.883 (30)

2.887 (36)

2.894 (50)

2.931 (95)

2.969 (40)

 σ2 (Å)

0.0019 (10)

0.0016 (24)

0.0024 (15)

0.0023 (27)

0.00323 (31)

0.0033 (50)

0.0078 (62)

0.0051 (40)

Fe-FeE

 CN

3

3

3

3

3

3

3

3

 R (Å)

2.975 (14)

2.977 (17)

2.987 (16)

2.992 (18)

2.998 (21)

2.991 (25)

2.979 (95)

2.987 (55)

 σ2 (Å)

0.0019 (10)

0.0025 (13)

0.0035 (13)

0.0035 (14)

0.0034 (16)

0.0041 (23)

0.0063 (17)

0.0118 (46)

Fe-FeC (1)

 CN

3

3

3

3

3

3

3

3

 R (Å)

3.391 (11)

3.397 (13)

3.397 (10)

3.399 (11)

3.403 (13)

3.398 (13)

3.398 (13)

3.410 (17)

 σ2 (Å)

0.0038 (8)

0.0044 (9)

0.0050 (7)

0.0051 (8)

0.0052 (9)

0.0052 (9)

0.0069 (11)

0.0067 (12)

Fe-FeC (2)

 CN

6

6

6

6

6

6

6

6

 R (Å)

3.687 (13)

3.683 (14)

3.685 (12)

3.688 (14)

3.693 (16)

3.686 (16)

3.688 (17)

3.679 (22)

 σ2 (Å)

0.0086 (9)

0.0092 (11)

0.0105 (10)

0.0111 (11)

0.0114 (13)

0.0112 (13)

0.0133 (16)

0.0147 (23)

 E0 (eV)

−2 (2)

−1 (2)

0 (2)

1 (2)

1 (2)

1 (2)

0 (2)

1 (2)

 Chi Sq

44

72

797

1118

128

63

22

21

 R-factor

0.0048

0.0045

0.0033

0.0038

0.0049

0.0048

0.0048

0.008