Clear experimental evidence of re-entrant spin glass state has been revealed in Er doped CeFe2 compounds. The zero field cooled - field cooled bifurcation in dc magnetization, frequency dependence of freezing temperature, relaxation in zero field cooled magnetization and presence of large remanence confirm the spin glass state in these compounds. Frequency dependence is found to follow the critical slowing down mechanism. The random substitution of Er and the change in the valence state of Ce along with an enhancement of the ferromagnetic component in the Fe sublattice seem to be responsible for the spin glass state. Using detailed experimental protocols, we also prove that the low temperature state in these compounds is not a magnetic glass. The absence of exchange bias gives an indication that there is no coexistence of ferromagnetism and spin glass state in these compounds. The RSG state is found to be associated with the randomly magnetized clusters instead of atomic level randomness.
Amorphous ferromagnetism and re-entrant magnetic glassiness in Sm$_{2}$Mo$_{2}$O$_{7}$: new insights into the electronic phase diagram of pyrochlore molybdates
本文讨论了Sm $_{2}$ Mo $_{2}$ O $_{7}$单晶的磁性。在文献中，一个传统的巡游铁磁态的钼$^{4+}$亚晶格低于$\sim 78$ K的报道。然而，我们的直流磁强计，μ子自旋谱（$μ^{+}$ SR）和高次谐波交流磁化率的结果毫不含糊地证明在这个阶段的高度无序的条件下，尽管结晶和化学顺序。这种无序的磁性状态与非晶铁磁合金有几个共同的特征。Sm $_{2}$ Mo $_{2}$ O $_{7}$的这种情况是支持的临界指数，主要是由我们的直流磁化数据的标度分析推导和确认的其他技术的过高的值。此外，$μ^{+}$ SR在微观尺度上检测到显著的静态磁无序。同时，交流磁化率的三次谐波分量在$\sim 78$ K附近的临界发散导致该磁相的玻璃性质的额外证据。最后，纵向弛豫的$μ^{+}$自旋极化（也支持交流磁化率的结果）的证据再入玻璃的功能类似于非晶铁磁体。
AC magnetic susceptibility study of a sigma-phase Fe65.9V34.1 alloy
研究了σ相Fe 65.9 V 34.1合金的交流磁化率随温度、频率和外加磁场的变化规律。有证据表明，它的磁性表现出折返行为的特征，即两个转变：第一次是在TC约312K时由顺磁态转变为共线铁磁态，第二次是在Tf约302K时转变为混合态（有时称为铁磁再入自旋玻璃），最后，在较低的温度（TRSG约60 K）转变为副本对称性被打破的状态。的Tf的频率依赖性是低于典型的自旋玻璃，一个功能，在光的高浓度的磁性载流子，可以理解的磁性集群之间的弱耦合。
Evidence for reentrant quantum paraelectric state preceded by a multiglass phase with non-classical exponent and magnetodielectric coupling in SrFe12O19
The magnetic phase diagram in the H-T coordinates has been determined for σ-Fe68V32 from the ZFC/FC magnetization measurements. The re-entrant character of magnetism, going from paramagnetic through ferromagnetic to spin-glass (SG) states, has been evidenced. The SG phase is magnetically heterogeneous, because two sub phases can be identified i.e. with the strong (SG-SI) and the weak (SG-WI) irreversibility. The ireversibility, T_irr and the crossover, T_cros, temperatures were quantitatively analysed using the mean-field theory and ϕ_irr=1.6(2) and ϕ_cros=0.91(9) values were obtained. A quali…
