Multiferroicity in Mn-deficient Ca3CoMnO6: The consequence of Fe substitution

Abstract

We present careful experiments on the multiferroicity in Ca 3 CoMn 0.92 O 6 by Fe substitution of Mn. It is revealed that a proper Fe substitution modulates the Co/Mn spin order, favoring the ferroelectricity. The multifold interactions between the intra-chain spins and inter-chain spins are analyzed. It is suggested that the Mn deficiency and Fe substitution can break the inter-chain interactions to some extent, resulting in the delicate competition between these mutual interactions. The modulation of the ionic (charge) disorder and spin frustration order is the core physics for improving the ferroelectric performance. V C 2013 AIP Publishing LLC.

Magnetotransport properties of Fe substituted Ca3CoMnO6

“…For acquiring acceptable magnetoelectric values for multiferroics, a high value of magnetostriction coefficient in its ferrite phase and dominating piezoelectric effect in its ferroelectric component are the key features for it [11]. Some samples may exhibit a non-collinear spin ordered mechanism which may contribute to non-zero polarizations as proposed by Dzyaloshinskii-Moriya (DM) interaction [12]. The symmetric exchange striction can be considered to be of greater relevance and typically stronger than DMI.…”

“…In the case of Ca 3 CoMnO 6 , the Co +2 ions are positioned at the trigonal prismatic sites and the Mn +4 ions occupy the octahedral sites and breaks the spatial inversion symmetry which leads to unusual physical properties, i.e. quantum tunneling effect of magnetism, electrical polarization via magnetostriction and magnetoelectric coupling [12,15,16].…”

“…However, dilute doping of Fe strengthens the Fe-Mn interactions which in turn enhances the polarization. Also, Fe +3 and Mn +4 possesses similar ionic radius but bigger difference in spin moment and thus it would be a proper choice to investigate the Fe substitution of Mn in Ca 3 CoMnO 6 [12]. O by co-precipitation method.…”