Ferromagnetism induced by lattice volume expansion and amorphization in EuTiO₃ thin films

Abstract

Abstract

Revisiting the fascinating properties of EuTiO 3 and its mixed crystals with SrTiO 3 : Possible candidates for novel functionalities

“…13). Such a behavior has been observed in various other perovskites and also in linear chain antiferromagnets [46][47][48][49][50]. The interpretation of those data was based on the fact that the 4f-4f interaction increases with increasing pressure and stabilizes the AFM order, whereas the superexchange via the bridging oxygen ions is considered to be less effective.…”

“…There are indications that on thin films the occurrence of both orderings is possible, if the samples are sufficiently strained [46,47]. These data were supported by amorphization of ETO samples which exhibit lattice volume expansions and show ferromagnetic ordering [48]. In contrast to the above experiments we investigated the low temperature phase transition as a function of pressure, motivated by the fact that in semiconducting cubic Eu chalcogenides the systems change their magnetic states from ferromagnetic (FM) to AFM with increasing ionic radius [49].…”

On the resistance minimum in LaAlO$_3$/Eu$_{1-x}$La$_x$TiO$_3$/SrTiO$_3$ heterostructures

“…The oxide structures were grown by Pulsed Laser Deposition (PLD) on TiO 2 -terminated (001)-oriented STO. In the literature, two types of targets have been used to grow ETO, the pyrochlore material Eu 2 Ti 2 O 7 13,[23][24][25][26][27] , and the perovskite material EuTiO 3 [28][29][30][31] . In this work, we choose to work with the latter.…”

On the structure of grain/interphase boundaries and interfaces

“…In a recent study [ 16 ], it has been shown that lattice expansion or amorphization makes EuTiO 3 ferromagnetic, although the stable phase of crystalline EuTiO 3 is antiferromagnetic. Ferromagnetism increases with an increase in the lattice volume of EuTiO 3 .…”