Different Critical Exponents on Two Sides of a Transition: Observation of Crossover from Ising to Heisenberg Exchange in Skyrmion Host Cu_{2}OSeO_{3}.

We present experimental investigation on critical phenomena in Cu_{2}OSeO_{3} by analyzing the critical behavior of magnetization using a new method. This is necessary as a crossover from 3D Ising to 3D Heisenberg has been observed in Cu_{2}OSeO_{3}. The proposed method is applicable to explore the physics for a wide range of materials showing trivial or nontrivial critical behavior on two sides of the transition.

Multiple magnetic phase transitions with different universality classes in bilayer La[Formula: see text]Sr[Formula: see text]Mn[Formula: see text]O[Formula: see text] manganite.

Here, we report three magnetic transitions at 101 K (T[Formula: see text]), 246 K (T[Formula: see text]) and 295 K (T[Formula: see text]) in bilayer La[Formula: see text]Sr[Formula: see text]Mn[Formula: see text]O[Formula: see text]. The second order phase transitions have been identified at these transition points with the help of change in entropy analysis and modified Arrott plots (MAPs). The critical behavior around T[Formula: see text], T[Formula: see text] and T[Formula: see text] have been studied by MAPs and Kouvel-Fisher method.

Magnetism in quasi-two-dimensional tri-layer LaSrMnO manganite.

The tri-layer La[Formula: see text]Sr[Formula: see text]Mn[Formula: see text]O[Formula: see text] manganites of Ruddlesden-Popper (RP) series are naturally arranged layered structure with alternate stacking of ω-MnO[Formula: see text] (ω = 3) planes and rock-salt type block layers (La, Sr)[Formula: see text]O[Formula: see text] along c-axis. The dimensionality of the RP series manganites depends on the number of perovskite layers and significantly affects the magnetic and transport properties of the system. Generally, when a ferromagnetic material undergoes a magnetic phase transition from ferromagnetic to paramagnetic state, the magnetic moment of the system becomes zero above the transition temperature (T[Formula: see text]).

3D-Ising like ferromagnetism in skyrmionic-bubbles host infinite-layer LaSrMnO manganite perovskite.

The critical behavior of infinite-layer LaSrMnO of Ruddlesden-Popper series manganite has been studied around the transition temperature ([Formula: see text]). To reveal the universality class that explains the critical behavior in LaSrMnO several methods, such as modified Arrott plots, Kouvel-Fisher, entropy and critical isotherm analysis have been employed. The critical exponent [Formula: see text] for infinite-layer is obtained independently from critical magnetization isotherm and found to satisfy the Widom scaling relation [Formula: see text].