The present disclosure relates to P-type SnSe crystal capable of being used as thermoelectric refrigeration material and a preparation method thereof. The material is a Na-doped and Pb-alloyed SnSe crystal. A molar ratio of Sn, Se, Pb and Na is (1-x-y):1:y:x, where 0.015≤x≤0.025 and 0.05≤y≤0.11. The P-type SnSe crystal provided by the present disclosure is capable of being used as the thermoelectric refrigeration material. A power factor PF of the P-type SnSe crystal at a room temperature is ≥70 μWcm.sup.−1K.sup.−2, and ZT at the room temperature is ≥1.2. A single-leg temperature difference measurement platform built on the basis of the obtained SnSe crystal may realize a refrigeration temperature difference of 17.6 K at a current of 2 A. The present disclosure adopts a modified directional solidification method and uses a continuous temperature region for slow cooling to grow a crystal to obtain the large-sized high-quality SnSe crystal.

The present disclosure relates to P-type SnSe crystal capable of being used as thermoelectric refrigeration material and a preparation method thereof. The material is a Na-doped and Pb-alloyed SnSe crystal. A molar ratio of Sn, Se, Pb and Na is (1-x-y):1:y:x, where 0.015≤x≤0.025 and 0.05≤y≤0.11. The P-type SnSe crystal provided by the present disclosure is capable of being used as the thermoelectric refrigeration material. A power factor PF of the P-type SnSe crystal at a room temperature is ≥70 μWcm.sup.−1K.sup.−2, and ZT at the room temperature is ≥1.2. A single-leg temperature difference measurement platform built on the basis of the obtained SnSe crystal may realize a refrigeration temperature difference of 17.6 K at a current of 2 A. The present disclosure adopts a modified directional solidification method and uses a continuous temperature region for slow cooling to grow a crystal to obtain the large-sized high-quality SnSe crystal.

The present disclosure relates to P-type SnSe crystal capable of being used as thermoelectric refrigeration material and a preparation method thereof. The material is a Na-doped and Pb-alloyed SnSe crystal. A molar ratio of Sn, Se, Pb and Na is (1-x-y):1:y:x, where 0.015≤x≤0.025 and 0.05≤y≤0.11. The P-type SnSe crystal provided by the present disclosure is capable of being used as the thermoelectric refrigeration material. A power factor PF of the P-type SnSe crystal at a room temperature is ≥70 μWcm.sup.−1K.sup.−2, and ZT at the room temperature is ≥1.2. A single-leg temperature difference measurement platform built on the basis of the obtained SnSe crystal may realize a refrigeration temperature difference of 17.6 K at a current of 2 A. The present disclosure adopts a modified directional solidification method and uses a continuous temperature region for slow cooling to grow a crystal to obtain the large-sized high-quality SnSe crystal.

The present disclosure relates to P-type SnSe crystal capable of being used as thermoelectric refrigeration material and a preparation method thereof. The material is a Na-doped and Pb-alloyed SnSe crystal. A molar ratio of Sn, Se, Pb and Na is (1-x-y):1:y:x, where 0.015≤x≤0.025 and 0.05≤y≤0.11. The P-type SnSe crystal provided by the present disclosure is capable of being used as the thermoelectric refrigeration material. A power factor PF of the P-type SnSe crystal at a room temperature is ≥70 μWcm.sup.−1K.sup.−2, and ZT at the room temperature is ≥1.2. A single-leg temperature difference measurement platform built on the basis of the obtained SnSe crystal may realize a refrigeration temperature difference of 17.6 K at a current of 2 A. The present disclosure adopts a modified directional solidification method and uses a continuous temperature region for slow cooling to grow a crystal to obtain the large-sized high-quality SnSe crystal.

What is provided is a layered double hydroxide crystal for achieving higher ion-exchange capacity than that of the related art.

The layered double hydroxide crystal 1 according to the present embodiment is represented by Formula (1) and composed of a plurality of crystal grains 10 each of which has a lamination structure in which a plurality of plate-shaped crystals (11), (11), . . . are laminated, in which particle sizes of the plurality of crystal grains (10), (10), . . . are uniform on a microscale.

[Ni.sup.2+.sub.1-xFe.sup.3+.sub.x(OH).sub.2].[(Cl.sup.−).sub.X/2]  (1) (Where, 0.25<x≤0.9)

What is provided is a layered double hydroxide crystal for achieving higher ion-exchange capacity than that of the related art.

The layered double hydroxide crystal 1 according to the present embodiment is represented by Formula (1) and composed of a plurality of crystal grains 10 each of which has a lamination structure in which a plurality of plate-shaped crystals (11), (11), . . . are laminated, in which particle sizes of the plurality of crystal grains (10), (10), . . . are uniform on a microscale.

[Ni.sup.2+.sub.1-xFe.sup.3+.sub.x(OH).sub.2].[(Cl.sup.−).sub.X/2]  (1) (Where, 0.25<x≤0.9)

Methods for purifying reaction precursors used in the synthesis of inorganic compounds and methods for synthesizing inorganic compounds from the purified precursors are provided. Also provided are methods for purifying the inorganic compounds and methods for crystallizing the inorganic compounds from a melt. γ and X-ray detectors incorporating the crystals of the inorganic compounds are also provided.

The disclosure relates to a method for making an iron telluride including placing Fe, Bi, and Te in a reacting chamber as reacting materials. The reacting chamber is evacuated to be a vacuum with a pressure lower than 10 Pa. The reacting chamber is heated to a first temperature of 700 degrees Celsius to 900 degrees Celsius and keeping the first temperature for a period of 10 hours to 14 hours. Then the reacting chamber is cooled to a second temperature of 400 degrees Celsius to 700 degrees Celsius within 60 hours to 75 hours and keeping the second temperature for a period of 40 hours to 50 hours, to obtain a reaction product including a FeTe.sub.0.9 single crystal. The FeTe.sub.0.9 single crystal is separated from the reaction product.

The disclosure relates to a method for making an iron telluride including placing Fe, Bi, and Te in a reacting chamber as reacting materials. The reacting chamber is evacuated to be a vacuum with a pressure lower than 10 Pa. The reacting chamber is heated to a first temperature of 700 degrees Celsius to 900 degrees Celsius and keeping the first temperature for a period of 10 hours to 14 hours. Then the reacting chamber is cooled to a second temperature of 400 degrees Celsius to 700 degrees Celsius within 60 hours to 75 hours and keeping the second temperature for a period of 40 hours to 50 hours, to obtain a reaction product including a FeTe.sub.0.9 single crystal. The FeTe.sub.0.9 single crystal is separated from the reaction product.

The present disclosure relates to a silicon-based fusion composition used for a solution growth method for forming a silicon carbide single crystal, and represented by the following Formula 1, including silicon, a first metal (M1), scandium (Sc) and aluminum (Al):
Si.sub.aM1.sub.bSc.sub.cAl.sub.d  (Formula 1) wherein a is more than 0.4 and less than 0.8, b is more than 0.2 and less than 0.6, c is more than 0.01 and less than 0.1, and d is more than 0.01 and less than 0.1.