中国物理B ›› 2011, Vol. 20 ›› Issue (11): 117502-117502.doi: 10.1088/1674-1056/20/11/117502

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Effects of Fe doping on ac susceptibility of Pr0.75Na0.25MnO3

王继亮1, 张晶1, 王爽1, 关晶1, 李玉2, 戚大伟2, 程倩3   

  1. (1)College of Science, Northeast Forestry University, Harbin 150040, China; (2)College of Science, Northeast Forestry University, Harbin 150040, China; Post-doctoral Mobile Research Station of Forestry Engineering, Northeast Forestry University, Harbin 150040, China; (3)Material Science and Engineering College, Northeast Forestry University, Harbin 150040, China
  • 收稿日期:2011-08-29 修回日期:2011-09-02 出版日期:2011-11-15 发布日期:2011-11-15
  • 基金资助:
    Project supported by the Fundamental Research Funds for the Central Universities of China (Grant No. DL09BB31), the Open Project of Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, China (Grant No. LZUMMM2010004),the Fundamental Research Funds for the Central Universities of China (Grant No. DL09BB36), the National Natural Science Foundation of China (Grant No. 31170518), and the Research Fund of Heilongjiang Provincial Education Department (Grant No. 12513040).

Effects of Fe doping on ac susceptibility of Pr0.75Na0.25MnO3

Li Yu(李玉)a)b), Cheng Qian(程倩)c), Qi Da-Wei(戚大伟)a)b)†, Wang Ji-Liang(王继亮)a), Zhang Jing(张晶)a), Wang Shuang(王爽)a), and Guan Jing(关晶)a)   

  1. a College of Science, Northeast Forestry University, Harbin 150040, China; b Post-doctoral Mobile Research Station of Forestry Engineering, Northeast Forestry University, Harbin 150040, China; c Material Science and Engineering College, Northeast Forestry University, Harbin 150040, China
  • Received:2011-08-29 Revised:2011-09-02 Online:2011-11-15 Published:2011-11-15
  • Supported by:
    Project supported by the Fundamental Research Funds for the Central Universities of China (Grant No. DL09BB31), the Open Project of Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, China (Grant No. LZUMMM2010004),the Fundamental Research Funds for the Central Universities of China (Grant No. DL09BB36), the National Natural Science Foundation of China (Grant No. 31170518), and the Research Fund of Heilongjiang Provincial Education Department (Grant No. 12513040).

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摘要： Ac susceptibility at low temperatures of Pr0.75Na0.25Mn1-xFexO3 (0 ≤ x ≤ 0.30) is investigated. The peak value of the real component of ac susceptibility χ' at the freezing temperature Tf is suppressed with the increasing frequency. The peak value of χ' shows a linear relation between Tf and the logarithm of the frequency ω. The normalized slope P = ΔTf/TfΔlgω, which is much lower than canonical insulating spin glass systems in which 0.06 ≤ P ≤ 0.08. The peak value of the imaginary component of the ac susceptibility χ'' at Tf for the x = 0, 0.02, 0.30 samples increases with increasing frequency, suggesting a cluster glass ground state with a coexistence of charge-ordered phase and correlated ferromagnetic clusters in spin glass matrix. The peak value of χ'' at Tf for the x = 0.10 sample decreases with increasing frequency, suggesting a phase separation ground state. The peak value of χ'' at Tf for the x = 0.05 sample decreases with increasing frequency for ω ≤ 52 Hz and increases subsequently till 701 Hz, and then decreases with further increasing frequency for ω ≥ 1501 Hz. This complex behaviour is ascribed to the competition between the effects of large and little ferromagnetic clusters in the sample. The ground state of x = 0.05 sample is a transition state from cluster glass to phase separation.

关键词: magnetization, ac susceptibility, phase separation, cluster-glass

Abstract: Ac susceptibility at low temperatures of Pr$_{0.75}$Na$_{0.25}$Mn$_{1-x}$Fe$_{x}$O$_{3}$ ($0 \le  x \le 0.30$) is investigated. The peak value of the real component of ac susceptibility $\chi '$ at  the freezing  temperature $T_{\rm f }$ is suppressed with the increasing frequency. The peak value of $\chi '$ shows a linear relation between $T_{\rm f}$ and the logarithm of the frequency $\omega$. The normalized slope $P = \Delta T_{\rm  f }/T_{\rm f}\Delta {\rm lg}\omega $, which is much lower than canonical insulating spin glass systems in which $0.06 \le  P \le 0.08$. The peak value of the imaginary component of the ac susceptibility $\chi''$ at $T_{\rm f}$  for the $x = 0$, 0.02, 0.30 samples increases with increasing frequency, suggesting a cluster glass ground state with a coexistence of charge-ordered phase and correlated ferromagnetic clusters in spin glass matrix. The peak value of $\chi''$ at $ T_{\rm f}$ for the $x = 0.10$ sample decreases with increasing frequency, suggesting a phase separation ground state. The peak value of $\chi''$ at $ T_{\rm f}$ for the $x = 0.05$ sample decreases with  increasing frequency for $\omega \le 52$ Hz and increases subsequently till 701~Hz, and then decreases with further increasing frequency for $\omega \ge  1501$ Hz. This complex behaviour is ascribed to the competition between  the effects of large and little ferromagnetic clusters in the sample. The ground state of $x = 0.05$ sample is a transition state from cluster glass to phase separation.

Key words: magnetization, ac susceptibility, phase separation, cluster-glass

中图分类号:  (Spin glasses and other random magnets)

  • 75.50.Lk
75.60.Ej (Magnetization curves, hysteresis, Barkhausen and related effects) 75.30.Kz (Magnetic phase boundaries (including classical and quantum magnetic transitions, metamagnetism, etc.))