Compact Oxygen is formed at normal atmospheric pressure at temperatures below 54.36 K (-218.79 ° C, -361.82 ° F). Oxygen solid O 2 , such as liquid oxygen, is a clear substance with a blue sky color caused by absorption in the red part of the visible light spectrum.
Oxygen molecules have attracted attention because of the relationship between molecular magnetization and crystal structure, electronic structure, and superconductivity. Oxygen is the only simple diatomic molecule (and one of several molecules in general) to carry a magnetic moment. This makes solid oxygen very appealing, as it is considered a 'spin-controlled' crystal featuring an antiferromagnetic magnetic sequence at low-temperature phases. The magnetic properties of oxygen have been studied extensively. At very high pressures, solid oxygen changes from isolation to metallic state; and at very low temperatures, it even turns into a superconducting state. Structural investigations of solid oxygen began in 1920 and, at present, the six distinct phases of crystallography are clearly defined.
Compacted oxygen density ranges from 21 cm 3 /mol in -fase, up to 23.5 cm 3 /mol in -fase.
Video Solid oxygen
Fase
A total of six distinct phases of solid oxygen are known to exist:
- ? - phase: light blue - formed at 1 atm below 23.8 K, monoclinic crystal structure.
- ? - phase: dim blue becomes pink - is formed at 1 atm below 43.8 K, rhombohedral crystal structure, (at room temperature and high pressure start transformation into tetraoxygen).
- ? - phase: faint blue - formed at 1 atm below 54,36 K, cubic crystal structure.
- ? - phase: orange - is formed at room temperature by applying pressure of 9 GPa
- ? - phase: dark-red to black - is formed at room temperature at pressures greater than 10 GPa
- ? - phase: metallic - formed at pressures greater than 96 GPa
It is known that oxygen is compressed into a state called? -phase at room temperature by applying pressure, and with increasing pressure, -the phase undergoes phase-to-phase transition at 9 GPa and? -fase on 10 GPa; and, due to increased molecular interaction, color? -the phase turns pink, orange, then red (stable octanoloxase phase), and the darker the red becomes black with increasing pressure. Found that a metallic? -phase appears at 96 GPa when the oxygen-phase is further compressed.
Red oxygen
Since the oxygen pressure at room temperature increases to 10 GPa (1,450,377 psi), it undergoes a dramatic phase transition to a different allotrope. The volume decreases significantly, and changes color from sky-blue to deep red. This? -Fase was discovered in 1979, but its structure is not clear. Based on the infrared absorption spectrum, the researchers assume in 1999 that this phase consists of O
4 molecules in the crystal lattice. However, in 2006, it was shown by X-ray crystallography that this stable phase is known as ? oxygen or red oxygen is actually O
8 . No one predicts theoretically the structure: rhomboid O
8 cluster consisting of four O
2 molecule.
In this phase it shows a red-dark color, very strong infrared absorption, and magnetic collapse. It is also stable over a very large pressure domain and has been the subject of many X-ray diffraction, spectroscopic and theoretical studies. It has been shown to have C2/m monoclinic symmetry and infrared absorption behavior associated with oxygen molecular associations into larger units.
- Liquid oxygen is already used as an oxidant in rockets, and has speculated that red oxygen can make better oxidants, because of its higher energy density.
- Researchers think that this structure can greatly influence the investigation of elemental structures.
- This is a phase that is formed above 600 K at a pressure greater than 17 GPa.
- At 11 GPa, the length of the intra-cluster bond O
8 cluster is 0.234Ã, nm, and the inter-cluster distance is 0.266Ã, nm. (For comparison, the intra-molecule bond length of the oxygen molecule O
2 is 0.120 nm.) - Formation mechanism O
8 clusters found in work are unclear, and researchers think that the transfer of charges between oxygen molecules or the molecular moments of oxygen molecules has an important role in formation.
Metal oxygen
A? -phase appears at 96 GPa when? further-phase oxygen is compressed. This phase was discovered in 1990 by pressing oxygen to 132 GPa. The -phase with a metal cluster shows superconductivity at pressures above 100GPa and temperatures below 0.6K.
Maps Solid oxygen
References
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