Abstract: A material is presented that exhibits excellent corrosion resistance to supercritical ammonia and is suitable for a supercritical ammonia reactor. An Ni-based corrosion resistant alloy includes from 15% or more to 50% or less by mass of Cr and any one or both of Mo and W, wherein a [(content of Mo)+0.5×(content of W)] is from 1.5% or more to 8.5% or less by mass, a value of 1.8×[% content of Cr]/{[% content of Mo]+0.5×[% content of W]} is from 3.0 or more to 70.0 or less and the balance is Ni and an unavoidable impurity. The alloy may be used to configure a supercritical ammonia reactor or the material is coated on a surface that contacts with a supercritical ammonia fluid. The alloy exhibits excellent corrosion resistance to supercritical ammonia and a mineralizer added the supercritical ammonia. The safety and reliability of an apparatus can be improved, the producing cost can be reduced, the apparatus lifetime can be extended and the running cost can be reduced.

Abstract: An object of the present invention is to provide an artificial quartz member inhibited from suffering the decrease in transmittance in a laser light wavelength region which is caused by long-term irradiation with a laser light having a wavelength of 200 nm or shorter; and a process for producing the artificial quartz member. The invention provides an artificial quartz member for use as an optical element to be irradiated with a laser light having a wavelength of 200 nm or shorter, having an aluminum content of 200 ppb or lower.

Abstract: A zinc oxide based substrate satisfies a condition that impurities Si, C, Ge, Sn, and Pb which are Group IV elements each have a concentration of 1×1017 cm?3 or less. More preferably, the zinc oxide based substrate 2 satisfies a condition that impurities Li, Na, K, Rb, and Fr which are Group I elements each have a concentration of 1×1016 cm?3 or less. The impurity concentration of a zinc oxide based semiconductor grown on the zinc oxide based substrate can be reduced in this manner.

Abstract: To produce a zinc oxide single crystal having a sufficiently low lithium concentration and a high crystallinity. A zinc oxide crystal is grown by hydrothermal synthesis method using a solution having a lithium concentration of 1 ppm or less (weight basis), while suppressing a fluctuation range of crystal growth temperature within 5° C. or at a temperature within the range of 300 to 370° C.

Abstract: A manufacture method that can manufacture ZnO based compound semiconductor crystal of good quality. A ZnO substrate is prepared to have a principal surface made of a plurality of terraces of (0001) planes arranged stepwise along an m-axis direction, the envelop of the principal surface being inclined relative to the (0001) plane by about 2 degrees or less. ZnO based compound semiconductor crystal is grown on the principal surface.

Abstract: An object of the present invention is to provide an artificial quartz member inhibited from suffering the decrease in transmittance in a laser light wavelength region which is caused by long-term irradiation with a laser light having a wavelength of 200 nm or shorter; and a process for producing the artificial quartz member. The invention provides an artificial quartz member for use as an optical element to be irradiated with a laser light having a wavelength of 200 nm or shorter, having an aluminum content of 200 ppb or lower.

Abstract: A manufacture method that can manufacture ZnO based compound semiconductor crystal of good quality. A ZnO substrate is prepared to have a principal surface made of a plurality of terraces of (0001) planes arranged stepwise along an m-axis direction, the envelop of the principal surface being inclined relative to the (0001) plane by about 2 degrees or less. ZnO based compound semiconductor crystal is grown on the principal surface.

Abstract: Provided is a single crystal with a hexagonal wurtzite structure which is useful as a substrate for various devices and has high purity and is uniform. The single crystal with a hexagonal wurtzite structures which is obtained by a crystal growth on at least an m-plane of a columnar seed crystal and represented by AX (A representing an electropositive element and X representing an electronegative element) is characterized in that a variation in the concentration of a metal other than the electropositive element A and having a concentration of 0.1 to 50 ppm is within 100%.

Abstract: An objective of the present invention is to provide a zinc oxide (ZnO) single crystal whose electroconductivity is excellent and which has a high quality. The invention relates to a zinc oxide single crystal whose concentration of metals other than zinc in the crystal fulfills the following equation: [?cM]/[+cM]?3 wherein M is a metal other than zinc, [?cM] is a concentration of M in a ?c region in the zinc oxide crystal, and [+cM] is a concentration of M in a +c region in the zinc oxide crystal.

Abstract: A temperature measurement device is provided with a temperature sensing element which contains a quartz resonator having a quartz oscillating crystal whose ratio of width to thickness is in the range of 9.48 to 9.69, and an antenna which receives stimulus for the quartz oscillating crystal and transmits waves of reverberatory oscillation. The temperature measurement device is capable of measuring temperatures in the range of normal room temperature to extremely low temperatures (4.degree. K.).