MAGNESIUM OXIDE (MgO)

Oxide ceramics such as MgO or Al2O3, which have relatively high melting points, and are composed of low Z elements may be used as limiters, insulators and as windows, lenses and mirrors for directing optical beams.

n the latter case it is necessary to investigate the radiation damage of the optical properties of these ceramics through exposure to neutrons. Optical properties of high - purity crystals of MgO and Al2O3 irradiated by 14 MeV neutrons have previously been reported by Chen et al, Evans and Stepelbroek respectively, refs [1-2]. The absorption spectra of these irradiated crystals resembled those irradiated in fission reactors. However, in these materials the production rates of anion vacancy centers (F+, F and F2 centers) by irradiation with 14 MeV neutrons were about twice those irradiated with fission neutrons.

GENERAL PROPERTIES - MAGNESIUM OXIDE

Physical properties

Melting Point : 2000 +/- 30 C
Density at RT : 3.9 g/cm3
Apparent Porosity : 0 %
Water Absorption-Saturation : 0 %

Electrical properties

Dielectric Constant : 9.0 - 10.1
Dielectric Strength : 10 - 35 kV/mm
Volume Resistivity @ 20 C : > 1014 [[Omega]] cm

Thermal properties

Thermal Conductivity @ 20 C : 28 - 35 W/m-K
Thermal Expansivity, 20 - 1000 C : 8.0 x10-6m/m-K
Upper Continuous Use Temperature : 1800 C

Mechanical properties

Compressive Strength : 2200 - 2600 MPa
Shear Strength : 330 MPa
Hardness-Vickers : 1500 - 1650 kgf/mm2
Tensile Modulus : 330 - 400 GPa


References

  1. Y. Chen, M.M. Abraham, M.T.Robinson, J.B. Mitchell and R.A. Van Konynenburg, Proc. Intern. Conf. on Radiation Effects and Tritium Tech. Fusion Reactors, Gatlinburg, TN. (1975), USERDA CONF 750989 Vol. II. p. 492.

  2. B.D. Evans and M. Stapelbroek, J. Nucl. Mater. 85/86 (1979) 497.