Manifestation of Nonconventional Magnetic Interaction in Electron-Doped Ca0.85Dy0.15MnO3 from Magnetic Properties and Critical Behavior Analysis

Detailed experimental investigation of magnetic properties and critical behavior of electron-doped Ca0.85Dy0.15MnO3 (CDMO) compound around phase transition is carried out. The positive Landau coefficient b(T) reflects 2nd order transition in CDMO compound. Second-order magnetic phase transition in a CDMO sample is also confirmed by positive slopes of Arrott plot. The critical exponents of the CDMO compound have been estimated based on different techniques like the modified Arrott plot (MAP), Kouvel-Fisher method, and critical isotherm analysis. The estimated values of critical exponents β, γ, and δ deviate significantly from those values which correspond to conventional universality classes like the 3d Heisenberg model, 3d Ising model, three-dimensional mean field model, and tricritical mean field model. These unusual values of critical exponents suggest the presence of nonconventional magnetic interaction in the CDMO sample.