Role of anisotropic exchange and site disorder in YBaCuFeO5: A Monte-Carlo study

Motivated by the recent debate on the existence of type-II multiferroicity in YBaCuFeO5(YBCFO) driven by incommensurate spiral magnetic ordering up to temperatures higher than room temperature, we have investigated the magnetic phase transition of YBCFO using Monte-Carlo simulation on classical Heisenberg XXZ model. We have studied the role of anisotropic exchange and Fe-Cu site disorder on the commensurate-incommensurate magnetic phase transition. Using various exchange interactions obtained from density functional theory, our Monte-Carlo simulations show that both anisotropic exchange and site disorder play significant roles in giving rise to spiral magnetic ordering at lower temperatures.