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Unexpected observation of splitting of skyrmion phase in Zn doped Cu2OSeO3.

Wu HC, Wei TY, Chandrasekhar KD, Chen TY, Berger H, Yang HD - Sci Rep (2015)

Bottom Line: The effect of Zn doping upon saturation magnetization (MS) indicates that the Zn favors to occupying Cu(II) square pyramidal crystallographic site.The Zn doping concentration is found to affect greatly the M-T and χ'ac-T.H curves.

View Article: PubMed Central - PubMed

Affiliation: Department of Physics, National Sun Yat-Sen University, Kaohsiung, 804 Taiwan.

ABSTRACT
Polycrystalline (Cu1-xZnx)2OSeO3 (0≤x≤0.2) samples were synthesized using solid-state reaction and characterized by X-ray diffraction (XRD). The effect of Zn doping upon saturation magnetization (MS) indicates that the Zn favors to occupying Cu(II) square pyramidal crystallographic site. The AC susceptibility (χ'ac) was measured at various temperatures (χ'ac-T) and magnetic field strengths (χ'ac-H). The Zn doping concentration is found to affect greatly the M-T and χ'ac-T. The skyrmion phase has been inferred from the χ'ac-H data, and then indicated within the H-T phase diagrams for various Zn doping concentrations. The striking and unexpected observation is that the skyrmion phase region becomes split upon Zn doping concentration. Interestingly, second conical boundary accompanied by second skyrmion phase was also observed from dχ'ac/dH vs. H curves. Atomic site disorder created by the chemical doping modulates the delicate magnetic interactions via change in the Dzyaloshinskii-Moriya (DM) vector of distorted Cu(II) square pyramidal, thereby splitting of skyrmion phase might occur. These findings illustrate the potential of using chemical and atomic modification for tuning the temperature and field dependence of skyrmion phase of Cu2OSeO3.

No MeSH data available.


Related in: MedlinePlus

(a) M vs. T (b) χ′ac vs. T curves for (Cu1−xZnx)2OSeO3 (0 ≤ x ≤ 0.2). The dashed lines in (b) added as a guide to the eye for variation of magnetic transition temperatures with Zn doping.
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f3: (a) M vs. T (b) χ′ac vs. T curves for (Cu1−xZnx)2OSeO3 (0 ≤ x ≤ 0.2). The dashed lines in (b) added as a guide to the eye for variation of magnetic transition temperatures with Zn doping.

Mentions: Figure 3 shows the M-T and χ′ac–T curves for (Cu1−xZnx)2OSeO3 (0 ≤ x ≤ 0.2). For x = 0, the M-T and χ′ac–T curves are in good agreement with those of measured in single crystal Cu2OSeO329. Moreover, both M-T and χ′ac–T are changed correspondingly and systematically with Zn doping concentration x. Just below ferrimagnetic transition TC ~ 58 K, a clear peak appeared at 56 K shown in χ′ac–T for x = 0 is the hallmark signature of skyrmion phase30. It is noted that the peak is lowered in temperature and becomes fainter with increasing x. On the other hand, a second smaller but notable peak is developed as x ≥ 0.02 and shifted towards lower temperature with increasing x. These results clearly hint the possible formation of second skyrmion phase when x ≥ 0.02.


Unexpected observation of splitting of skyrmion phase in Zn doped Cu2OSeO3.

Wu HC, Wei TY, Chandrasekhar KD, Chen TY, Berger H, Yang HD - Sci Rep (2015)

(a) M vs. T (b) χ′ac vs. T curves for (Cu1−xZnx)2OSeO3 (0 ≤ x ≤ 0.2). The dashed lines in (b) added as a guide to the eye for variation of magnetic transition temperatures with Zn doping.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4563258&req=5

f3: (a) M vs. T (b) χ′ac vs. T curves for (Cu1−xZnx)2OSeO3 (0 ≤ x ≤ 0.2). The dashed lines in (b) added as a guide to the eye for variation of magnetic transition temperatures with Zn doping.
Mentions: Figure 3 shows the M-T and χ′ac–T curves for (Cu1−xZnx)2OSeO3 (0 ≤ x ≤ 0.2). For x = 0, the M-T and χ′ac–T curves are in good agreement with those of measured in single crystal Cu2OSeO329. Moreover, both M-T and χ′ac–T are changed correspondingly and systematically with Zn doping concentration x. Just below ferrimagnetic transition TC ~ 58 K, a clear peak appeared at 56 K shown in χ′ac–T for x = 0 is the hallmark signature of skyrmion phase30. It is noted that the peak is lowered in temperature and becomes fainter with increasing x. On the other hand, a second smaller but notable peak is developed as x ≥ 0.02 and shifted towards lower temperature with increasing x. These results clearly hint the possible formation of second skyrmion phase when x ≥ 0.02.

Bottom Line: The effect of Zn doping upon saturation magnetization (MS) indicates that the Zn favors to occupying Cu(II) square pyramidal crystallographic site.The Zn doping concentration is found to affect greatly the M-T and χ'ac-T.H curves.

View Article: PubMed Central - PubMed

Affiliation: Department of Physics, National Sun Yat-Sen University, Kaohsiung, 804 Taiwan.

ABSTRACT
Polycrystalline (Cu1-xZnx)2OSeO3 (0≤x≤0.2) samples were synthesized using solid-state reaction and characterized by X-ray diffraction (XRD). The effect of Zn doping upon saturation magnetization (MS) indicates that the Zn favors to occupying Cu(II) square pyramidal crystallographic site. The AC susceptibility (χ'ac) was measured at various temperatures (χ'ac-T) and magnetic field strengths (χ'ac-H). The Zn doping concentration is found to affect greatly the M-T and χ'ac-T. The skyrmion phase has been inferred from the χ'ac-H data, and then indicated within the H-T phase diagrams for various Zn doping concentrations. The striking and unexpected observation is that the skyrmion phase region becomes split upon Zn doping concentration. Interestingly, second conical boundary accompanied by second skyrmion phase was also observed from dχ'ac/dH vs. H curves. Atomic site disorder created by the chemical doping modulates the delicate magnetic interactions via change in the Dzyaloshinskii-Moriya (DM) vector of distorted Cu(II) square pyramidal, thereby splitting of skyrmion phase might occur. These findings illustrate the potential of using chemical and atomic modification for tuning the temperature and field dependence of skyrmion phase of Cu2OSeO3.

No MeSH data available.


Related in: MedlinePlus