ハフニウム

72
Hf
4
周期
6
ブロック
d
陽子
電子
中性子
72
72
106
一般特性
原子番号
72
原子量
178.49
質量数
178
カテゴリ
遷移元素
灰色
放射性
いいえ
From Hafinia, the Latin name for Copenhagen
結晶構造
六方最密構造
歴史
In 1911, Georges Urbain claimed to have found the element in rare-earth residues which was shown later to be a mixture of already discovered lanthanides.

Dirk Coster and George de Hevesy found it by X-ray spectroscopic analysis in Norwegian zircon in 1922.

Anton Eduard van Arkel and Jan Hendrik de Boer were the first to prepare metallic hafnium by passing hafnium tetra-iodide vapor over a heated tungsten filament in 1924.
電子殻
2, 8, 18, 32, 10, 2
電子配置
[Xe] 4f14 5d2 6s2
Hf
In powdered form, hafnium is pyrophoric and can ignite spontaneously in air
物理特性
固体
密度
13.31 g/㎝3
融点
2506.15 K | 2233 °C | 4051.4 °F
沸点
4876.15 K | 4603 °C | 8317.4 °F
融解熱
25.5 kJ/mol
蒸発熱
630 kJ/mol
熱容量
0.144 J/g·K
地殻中における存在比
0.00033%
宇宙空間における存在比
7×10-8%
Electrolytic
画像の出典: Images-of-elements
Electrolytic hafnium
CAS登録番号
7440-58-6
PubChem CID Number
23986
原子特性
原子半径
159 pm
共有結合半径
175 pm
電気陰性度
1.3 (ポーリングの値)
イオン化エネルギー
6.8251 eV
モル体積
13.6 ㎝3/mol
熱伝導率
0.23 W/㎝·K
酸化数
2, 3, 4
用途
Hafnium oxide-based compounds are being introduced into silicon-based chips to produce smaller, more energy efficient and performance packed processors.

Most of the hafnium produced is used in the production of control rods for nuclear reactors.

Hafnium is also used in photographic flash bulbs, light bulb filaments, and in electronic equipment as cathodes and capacitors.
Hafnium is considered to be non-toxic
同位体
安定同位体
176Hf, 177Hf, 178Hf, 179Hf, 180Hf
不安定同位体
153Hf, 154Hf, 155Hf, 156Hf, 157Hf, 158Hf, 159Hf, 160Hf, 161Hf, 162Hf, 163Hf, 164Hf, 165Hf, 166Hf, 167Hf, 168Hf, 169Hf, 170Hf, 171Hf, 172Hf, 173Hf, 174Hf, 175Hf, 181Hf, 182Hf, 183Hf, 184Hf, 185Hf, 186Hf, 187Hf, 188Hf