Chloride-induced controllable method for preparing transition-metal silicide material with specific crystal phase

Abstract

The invention relates to a chloride-induced controllable method for preparing a transition-metal silicide material with a specific crystal phase. The method comprises the steps of putting activated carbon which is dipped with barium chloride or calcium chloride and iron, copper, cobalt or nickel, or a silicon oxide precursor into a quartz tube reactor, firstly processing metal by using high-purity hydrogen gas (H2), carrying out full reduction at the temperature of 500 DEG C, then, introducing mixed gas of SiCl4 and H2, of which the mole ratio is 1: (6-8), into the reactor at the gaseous hourly space velocity of 5,000-20,000 / min and the pressure of 0.1-1.0MPa, and reacting for 3-8 hours while controlling the temperature to be 500-900 DEG C, thereby preparing transition-metal silicide. The transition-metal silicide prepared by the method can be expected to provide a support for the related researches and applications of transition-metal silicides with specific crystal phases.

Description

technical field [0001] The invention relates to a new method for controllably synthesizing a transition metal silicide material of a specific crystal phase, in particular a system for inducing the formation of a transition metal silicide material of a specific crystal phase by introducing a chloride salt and its controllable synthesis conditions. Background technique [0002] Transition metal (iron, copper, cobalt, nickel, etc.) silicides have important research and application values ​​in semiconductors, magnetic materials, solar energy, and catalytic industries. The applications of such materials in these fields are based on their special crystal phase structures. Since transition metal silicides need to be prepared by complex physical or chemical methods in a high-temperature, gas-solid multiphase system, the crystal phase composition of the product is usually relatively complex. Taking the preparation of nickel silicide as an example, the products are mostly nickel silici...

AI Technical Summary

Problems solved by technology

Since transition metal silicides need to be prepared by complex physical or chemical methods in a high-temperature, gas-solid multiphase system, the crystal phase composition of the product is usually relatively complex. Taking the preparation of nickel silicide as an example, the products are mostly nickel silicide (NiSi), silicide Nickel (Ni 2 Si), nickel silicide (Ni 3 Si) and other mixed crystal phases exist, and the existing preparation system is difficult to realize the synthesis of specific crystal phases for specific applications, especially single crystal phase transition metal silicide materials. This problem has become the main factor limiting the application of transition metal silicides. Therefore, the development of new systems or new methods capable of controllably synthesizing transition metal silicides with specific crystal phases plays an important supporting role in the industrial application of transition metal silicide materials.