摘要
Ac susceptibility at low temperatures of Pro.75Nao.25MnO3-xFexO3 （0 ≤ x ≤0.30） is investigated. The peak value of the real component of ac susceptibility X＇ at the freezing temperature Tf is suppressed with the increasing frequency. The peak value of X＇ shows a linear relation between Tf and the logarithm of the frequency ω. The normalized slope P = △Tf/Tf△lgco, 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 X＂ 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 ofx＂ at Tf for the x = 0.10 sample decreases with increasing frequency, suggesting a phase separation ground state. The peak value of X＂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.
Ac susceptibility at low temperatures of Pro.75Nao.25MnO3-xFexO3 （0 ≤ x ≤0.30） is investigated. The peak value of the real component of ac susceptibility X＇ at the freezing temperature Tf is suppressed with the increasing frequency. The peak value of X＇ shows a linear relation between Tf and the logarithm of the frequency ω. The normalized slope P = △Tf/Tf△lgco, 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 X＂ 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 ofx＂ at Tf for the x = 0.10 sample decreases with increasing frequency, suggesting a phase separation ground state. The peak value of X＂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.
基金
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)
the Research Fund of Heilongjiang Provincial Education Department(Grant No.12513040)
