Technetium – Crystal Structure

Periodic Table of Elements - crystal structure
1
H

Hydrogen

hexagonal

2
He

Helium

hcp

3
Li

Lithium

bcc

4
Be

Beryllium

hcp

5
B

Boron

rhombohedral

6
C

Carbon

hexagonal

7
N

Nitrogen

hexagonal

8
O

Oxygen

cubic

9
F

Fluorine

cubic

10
Ne

Neon

fcc

11
Na

Sodium

bcc

12
Mg

Magnesium

hcp

13
Al

Aluminium

fcc

14
Si

Silicon

diamond-cubic

15
P

Phosphorus

bcc

16
S

Sulfur

orthorhombic

17
Cl

Chlorine

orthorhombic

18
Ar

Argon

fcc

19
K

Potassium

bcc

20
Ca

Calcium

fcc

21
Sc

Scandium

hcp

22
Ti

Titanium

hcp

23
V

Vanadium

bcc

24
Cr

Chromium

bcc

25
Mn

Manganese

bcc

26
Fe

Iron

bcc

27
Co

Cobalt

hcp

28
Ni

Nickel

fcc

29
Cu

Copper

fcc

30
Zn

Zinc

hcp

31
Ga

Gallium

orthorhombic

32
Ge

Germanium

diamond-cubic

33
As

Arsenic

rhombohedral

34
Se

Selenium

hexagonal

35
Br

Bromine

orthorhombic

36
Kr

Krypton

fcc

37
Rb

Rubidium

bcc

38
Sr

Strontium

fcc

39
Y

Yttrium

hcp

40
Zr

Zirconium

hcp

41
Nb

Niobium

bcc

42
Mo

Molybdenum

bcc

43
Tc

Technetium

hcp

44
Ru

Ruthenium

hcp

45
Rh

Rhodium

fcc

46
Pd

Palladium

fcc

47
Ag

Silver

fcc

48
Cd

Cadmium

hcp

49
In

Indium

bct

50
Sn

Tin

bct

51
Sb

Antimony

rhombohedral

52
Te

Tellurium

hexagonal

53
I

Iodine

orthorhombic

54
Xe

Xenon

fcc

55
Cs

Caesium

bcc

56
Ba

Barium

bcc

57-71

 

Lanthanoids

 

72
Hf

Hafnium

hcp

73
Ta

Tantalum

bcc

74
W

Tungsten

bcc

75
Re

Rhenium

hcp

76
Os

Osmium

hcp

77
Ir

Iridium

fcc

78
Pt

Platinum

fcc

79
Au

Gold

fcc

80
Hg

Mercury

rhombohedral

81
Tl

Thallium

hcp

82
Pb

Lead

fcc

83
Bi

Bismuth

rhombohedral

84
Po

Polonium

rhombohedral

85
At

Astatine

fcc

86
Rn

Radon

fcc

87
Fr

Francium

bcc

88
Ra

Radium

bcc

89-103

 

Actinoids

 

104
Rf

Rutherfordium

hcp

105
Db

Dubnium

bcc

106
Sg

Seaborgium

bcc

107
Bh

Bohrium

hcp

108
Hs

Hassium

hcp

109
Mt

Meitnerium

fcc

110
Ds

Darmstadtium

bcc

111
Rg

Roentgenium

bcc

112
Cn

Copernicium

bcc

113
Nh

Nihonium

hcp

114
Fl

Flerovium

fcc

115
Mc

Moscovium

 

116
Lv

Livermorium

 

117
Ts

Tennessine

 

118
Og

Oganesson

 

57
La

Lanthanum

double hcp

58
Ce

Cerium

double hcp

59
Pr

Praseodymium

double hcp

60
Nd

Neodymium

double hcp

61
Pm

Promethium

double hcp

62
Sm

Samarium

rhombohedral

63
Eu

Europium

bcc

64
Gd

Gadolinium

hcp

65
Tb

Terbium

hcp

66
Dy

Dysprosium

hcp

67
Ho

Holmium

hcp

68
Er

Erbium

hcp

69
Th

Thulium

hcp

70
Yb

Ytterbium

fcc

71
Lu

Lutetium

hcp

89
Ac

Actinium

fcc

90
Th

Thorium

fcc

91
Pa

Protactinium

bct

92
U

Uranium

orthorhombic

93
Np

Neptunium

orthorhombic

94
Pu

Plutonium

monoclinic

95
Am

Americium

double hcp

96
Cm

Curium

double hcp

97
Bk

Berkelium

double hcp

98
Cf

Californium

double hcp

99
Es

Einsteinium

fcc

100
Fm

Fermium

fcc

101
Md

Mendelevium

fcc

102
No

Nobelium

fcc

103
Lr

Lawrencium

hcp

Technetium – Crystal Structure

A possible crystal structure of Technetium is hexagonal close-packed structure.

crystal structures - FCC, BCC, HCP

In metals, and in many other solids, the atoms are arranged in regular arrays called crystals. A crystal lattice is a repeating pattern of mathematical points that extends throughout space. The forces of chemical bonding causes this repetition. It is this repeated pattern which control properties like strength, ductility, density, conductivity (property of conducting or transmitting heat, electricity, etc.), and shape. There are 14 general types of such patterns known as Bravais lattices.

The three most common basic crystal patterns are:

  • Body-centered Cubic. In a body-centered cubic (BCC) arrangement of atoms, the unit cell consists of eight atoms at the corners of a cube and one atom at the body center of the cube. In a body-centered cubic arrangement, a unit cell contains (8 corner atoms × ⅛) + (1 center atom × 1) = 2 atoms. The packing is more efficient (68%) than simple cubic and the structure is a common one for alkali metals and early transition metals. Metals containing BCC structures include ferrite, chromium, vanadium, molybdenum, and tungsten. These metals possess high strength and low ductility.
  • Face-centered Cubic.In a face-centered cubic (FCC) arrangement of atoms, the unit cell consists of eight atoms at the corners of a cube and one atom at the center of each of the faces of the cube. In a face-centered cubic arrangement, a unit cell contains (8 corner atoms × ⅛) + (6 face atoms × ½) = 4 atoms. This structure, along with its hexagonal relative (hcp), has the most efficient packing (74%). Metals containing FCC structures include austenite, aluminum, copper, lead, silver, gold, nickel, platinum, and thorium. These metals possess low strength and high ductility.
  • Hexagonal Close-packed. In a hexagonal close-packed (HCP) arrangement of atoms, the unit cell consists of three layers of atoms. The top and bottom layers contain six atoms at the corners of a hexagon and one atom at the center of each hexagon. The middle layer contains three atoms nestled between the atoms of the top and bottom layers, hence, the name close-packed. Hexagonal close packed (hcp) is one of the two simple types of atomic packing with the highest density, the other being the face centered cubic (fcc). However, unlike the fcc, it is not a Bravais lattice as there are two nonequivalent sets of lattice points. Metals containing HCP structures include beryllium, magnesium, zinc, cadmium, cobalt, thallium, and zirconium. HCP metals are not as ductile as FCC metals.