DC Magnetic Properties of the Ho doped ZnO Compounds

AKYOL M., EKİCİBİL A., Kiymac K.

JOURNAL OF SUPERCONDUCTIVITY AND NOVEL MAGNETISM, cilt.26, sa.11, ss.3257-3262, 2013 (SCI-Expanded, Scopus)

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 26 Sayı: 11
  • Basım Tarihi: 2013
  • Doi Numarası: 10.1007/s10948-013-2135-2
  • Dergi Adı: JOURNAL OF SUPERCONDUCTIVITY AND NOVEL MAGNETISM
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.3257-3262
  • Anahtar Kelimeler: ZnO, Semiconductors, Magnetic hysteresis, DC susceptibility, Effective moment, THIN-FILMS, FERROMAGNETISM, TEMPERATURE, FIELD, BULK
  • Çukurova Üniversitesi Adresli: Evet

Özet

In this work, we report on the DC magnetic properties of Ho doped ZnO, Zn0.8-4x Ho (x) O (y) (0.05a parts per thousand currency signxa parts per thousand currency sign0.10), polycrystalline samples prepared by the so-called solid state reaction method. Magnetic measurements, M-H and M-T, done by using a PPMS magnetometer, show a paramagnetic behavior including indirect antiferromagnetic coupling between some Ho3+ magnetic moments. In other words, the negative values of the Curie-Weiss temperatures, theta, for the polycrystalline samples with six different Ho concentrations indicate that there is an effective antiferromagnetic coupling among the magnetic moments of Ho3+ ions. However, the decrease in the magnitude of theta with increasing x indicates that this coupling decreases with increasing amount of Ho in the compounds. Furthermore, the effective magnetic moments, mu (eff), per Ho atom calculated from the 1/chi-T curves gradually increase with increasing concentration. Therefore, the trends of the magnitudes of theta, and mu (eff) values clearly indicate that apart from the antiferromagnetic coupling there is also an increasing contribution of a ferromagnetic coupling with increasing x. Hence, one may also conclude that the compounds studied seem to have a kind of spin-glass behavior.

In this work, we report on the DC magnetic properties of Ho doped ZnO, Zn0.8-4x Ho x O y (0.05≤x≤0.10), polycrystalline samples prepared by the so-called solid state reaction method. Magnetic measurements, M-H and M-T, done by using a PPMS magnetometer, show a paramagnetic behavior including indirect antiferromagnetic coupling between some Ho3+ magnetic moments. In other words, the negative values of the Curie-Weiss temperatures, θ, for the polycrystalline samples with six different Ho concentrations indicate that there is an effective antiferromagnetic coupling among the magnetic moments of Ho3+ ions. However, the decrease in the magnitude of θ with increasing x indicates that this coupling decreases with increasing amount of Ho in the compounds. Furthermore, the effective magnetic moments, μ eff, per Ho atom calculated from the 1/χ-T curves gradually increase with increasing concentration. Therefore, the trends of the magnitudes of θ, and μ eff values clearly indicate that apart from the antiferromagnetic coupling there is also an increasing contribution of a ferromagnetic coupling with increasing x. Hence, one may also conclude that the compounds studied seem to have a kind of spin-glass behavior.