Abstract
SmB6 nanowires, as a prototype of nanostructured topological Kondo insulator, have shown rich novel physical phenomena relating to their surface. Catalyst-assisted chemical vapor deposition (CVD) is a common approach to prepare SmB6 nanowires and Ni is the most popular catalyst used to initiate the growth of SmB6 nanowires. Here, we study the effect of growth mechanism on the surface of SmB6 nanowires synthesized by CVD. Two types of SmB6 nanowires are obtained when using Ni as the catalyst. In addition to pure SmB6 nanowires without Ni impurity, a small amount of Ni is detected on the surface of some SmB6 nanowires by element analysis with transmission electron microscopy. In order to eliminate the possible distribution of Ni on nanowire surface, we synthesize single crystalline SmB6 nanowires by CVD without using catalyst. The difference between catalyst-assisted and catalyst-free growth mechanism is discussed.
Highlights
Topological insulator has attracted much interest in the field of condensed matter physics and material science recently because of its fundamentally novel physical phenomena, such as nontrivial gapless surface states protected by time reversal symmetry [1,2,3]
The growth of SmB6 nanowires is realized on Ni-coated Si substrate in a way similar to the method reported in Ref. 10
Characterization reveals that single crystalline SmB6 nanowires are grown by chemical vapor deposition (CVD) with the help of Ni
Summary
Topological insulator has attracted much interest in the field of condensed matter physics and material science recently because of its fundamentally novel physical phenomena, such as nontrivial gapless surface states protected by time reversal symmetry [1,2,3]. If Ni, the most popular catalyst assisting the growth of boride nanowire [10,13,19,20,21], migrates along the nanowire surface, the time reversal symmetry in topological Kondo insulator SmB6 can be broken [1,22,23]. Such a problem has not been emphasized and studied in SmB6 nanowires. Single crystalline SmB6 nanowires are grown on SmB6 particles via vapor-solid (VS) mechanism
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