Shubnikov‐de Haas Effect in (Cd_1−x−yZn_xMn_y)₃As₂ under Pressure

Abstract

We have investigated the Shubnikov‐de Haas effect in single crystals of the group II‐V diluted magnetic semiconductors (Cd1−x−yZnxMny)AS2(x + y = 0.3, y = 0.06 and 0.08) at temperatures T = 4.2 to 16 K and magnetic fields B = 0 to 6.5 T under hydrostatic pressure p up to 14 kbar. Values of the cyclotron mass mc, the effective g‐factor g*, and the Dingle temperature TD have been determined. In both specimens a linear field dependence mc(B) = m c* + αB is observed, where m c* is independent of B but increases with pressure and where a does not depend on p and B. Additionally, pressure dependencies of g*, TD and the Hall mobility μR are observed. The dependence of m c* and g*, on p is interpreted within the three‐band Kane model. The decrease of μR and TD with increasing pressure is consistent with an increase of m c*.

Anomalous cyclotron mass dependence on the magnetic field and Berry’s phase in (Cd1−x−yZnxMny)3As2solid solutions

“…In single crystals of prototype material (Cd 1−x Zn y ) 3 As 2 , the SdH oscillations showed no strong dependence on the crys tallographic direction [7]. In our studies of the magnetoresist ance for Mndoped samples [11,18,20] the variation between the samples of the same composition the cutted in different directions was not more than 1-2%. These differences are comparable to the errors occurring from nonequipotential and differences of the probes resistance.…”

Two-Dimensional Surface Topological Nanolayers and Dirac Fermions in Single Crystals of the Diluted Magnetic Semiconductor (Cd1−x−yZnxMny)3As2 (x + y = 0.3)

“…The wave vector k F can be estimated from the density of charge carriers n 2D , in accordance with a ration: n 2D = gk 2 F /4π, where g is the Landau bands degeneration factor. In our case, we can use g to be equal to 2 [42]. Finally, the values of k F were found for annealed and "as growth" samples of CZMA (Figure 5).…”

Magnetotransport of (Cd1?x?yZnxMny)3As2 under Pressure

“…Unoriented CZMA specimens were prepared from single crystal ingots obtained with the modified Bridgman method [2,3]. The dc magnetoresistance measurements were performed in the transverse (B c j) configuration with the six-probe method.…”

“…The galvanomagnetic properties of the narrow-gap n-type diluted magnetic semiconductor (DMS) (Cd 1± ±x± ±y Zn x Mn y ) 3 As 2 , briefly CZMA, have been investigated (i) in the vicinity of the gapless state for |E g | < 0.1 eV [1] and (ii) relatively far from it, at E g % 0.27 eV [2,3], by changing the gap E g with variation of the composition. In the latter case, corresponding to x + y = 0.3, the anomalous magnetic field dependence of the electron effective mass, m(B) = m(0) + aB where m(0)/m 0 = 0.03 to 0.05 and a/m 0 = (8 to 15) Â 10 ± ±3 1/T, has been observed.…”