FIG. 2:

Powder X-ray diraction peak at 2 theta = 96:65 deg. for polycrystalline samples with different Zn concentrations. Open circles: experimental data; dashed lines: single peak fits for individual phases; gray solid line: a sum of these fits; red line: difference between the global fit and the data. This demonstrates that the asymmetrical shape and splitting of diffraction peaks can only be modelled by multiple phases.

FIG. 3:

(a) Magnetization M vs T for polycrystalline samples, measured in a magnetic field of 25 mT. (b) The same for single crystal samples. (c) The temperature derivative of the M vs. T for polycrystalline samples, revealing multiple magnetic transitions. (open circles: experientially obtained data, blue, orange and green dotted lines: fits to distinct magnetic phases.) (d) The temperature derivative of the M vs T single crystal data, showing a single transition.

FIG. 4:

(Top) Critical temperature Tc (crosses) and lattice parameter a (circles) for each Cu2OSeO3 phase in polycrystalline samples, as a function of Zn-substitution. (Bottom) Volume fractions of each distinct phase in polycrystalline samples extracted from X-ray and DC magnetometry data.

FIG. 5:

(a)-(d) Real component of AC susceptibility ¬chi at a frequency of 10 Hz and driving field of 0.3 mT as a function of field B and temperature T for polycrystalline samples, showing the paramagnetic (P), ferrimagnetic (F), conical (C), helical (H) and skyrmion lattice (S) phases. (e)-(h). The same, but for single crystal samples. FIG. 6:(a) LF muSR spectra for 6.4% Zn-substituted polycrystalline Cu2OSeO3 measured at 54 K in 18 mT on a logarithmic scale with the background subtracted. Lines are guides to the eye. Relaxation rate lambda for LF muSR measurements of (b) pristine, (c) 6.4% and (d) 10.5% Zn-substituted Cu2OSeO3. Shaded regions indicate the location of the SkL phase derived from AC susceptibility.

• Related item in WRAP
• Publisher