Spin-glass behavior in Ni-doped La1.85Sr0.15CuO4
| Autor: | Roman Minikayev, Maciej Sawicki, Y. Syryanyy, Piotr Dziawa, A. Malinowski, V. L. Bezusyy |
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| Rok vydání: | 2011 |
| Předmět: | |
| Zdroj: | Physical Review B. 84 |
| ISSN: | 1550-235X 1098-0121 |
| DOI: | 10.1103/physrevb.84.024409 |
| Popis: | The dynamic and static magnetic properties of La${}_{1.85}$Sr${}_{0.15}$Cu${}_{1\ensuremath{-}y}$Ni${}_{y}$O${}_{4}$ with Ni concentration up to $y=0.63$ are reported. All the features that characterize the spin-glass (SG) behavior are found: bifurcation of the dc susceptibility $\ensuremath{\chi}$ versus temperature curve, a peak in the zero-field-cooling branch of this curve accompanied by a step in the imaginary part of the ac susceptibility ${\ensuremath{\chi}}_{\text{ac}}$, frequency dependence of the peak position in the real part of ${\ensuremath{\chi}}_{\text{ac}}$, and scaling behavior. The decay of remanent magnetization is described by a stretched-exponential function. The characteristic time from the critical slowing-down formula that governs the dynamics of the system suggests the existence of the spin clusters. The strongest interactions between the fluctuating entities are at $y$ equal to the charge-carrier concentration in the system. The SG transition temperature decreases linearly with decreasing $y$ for $y\ensuremath{\leqslant}0.30$ and extrapolates to 0 K at $y=0$, which means that Ni displays a magnetic character in the surrounding Cu-O network starting from the smallest concentration $y$. The static critical exponents characterizing the scaling behavior of the nonlinear part of $\ensuremath{\chi}$ lie between those typical for three-dimensional Ising-like and Heisenberg-like systems. |
| Databáze: | OpenAIRE |
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