6H to 3C Polytype Transformation in Silicon Carbide

Abstract

Temperature dependence of magnetic switching processes with multiple jumps in Fe/MgO (001) films is investigated by magnetoresistance measurements. When the temperature decreases from 300 K to 80 K, the measured three-jump hysteresis loops turn into two-jump loops. The temperature dependence of the fourfold in-plane magnetic anisotropy constant K 1 , domain wall pinning energy, and an additional uniaxial magnetic anisotropy constant K U are responsible for this transformation. The strengths of K 1 and domain wall pinning energy increase with decreasing temperature, but K U remains unchanged. Moreover, magnetization reversal mechanisms, with either two successive or two separate 90 • domain wall propagation, are introduced to explain the multi-jump magnetic switching process in epitaxial Fe/MgO(001) films at different temperatures.

3C-6H transformation in heated cubic silicon carbide 3C-SiC

“…The solid-state phase transformations can be studied in highly doped SiC crystals [6,14,15] and in the pure single crystals. The strong donor-acceptor pair (DAP) photoluminescence takes place in the highly doped SiC crystals [6,14] and the fine structure of PL associated with phase transformation can not be seen.…”

“…The strong donor-acceptor pair (DAP) photoluminescence takes place in the highly doped SiC crystals [6,14] and the fine structure of PL associated with phase transformation can not be seen.…”

Nanostructures in lightly doped silicon carbide crystals with polytypic defects

“…Great advances were reported in growing a single crystalline polytype by controlled sublimation and chemical vapor deposition [1][2][3]. Polytypic transformation in SiC was investigated by many authors [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19].…”

“…The phase transformation in highly doped by nitrogen 6H -SiC crystal and the mechanism of solidphase transition through formation of multilayer polytypes has been studied [5,14]. Syntax coalescence becomes a very important characteristic of α-polytype SiC crystals -the intergrowth of two or more polytypes when not only the major axis c but also the axis a coincide in the hexagonal structures.…”

“…Investigated in the paper [5] have been defects in heavily doped with nitrogen single crystals by using photoluminescence. However, correspondence between the PL spectra and mechanism of phase transformation has not been investigated.…”