Substrate-Dependent Growth of HoMnO₃ Films

Abstract

Manganites with small rare earths (RE ¼ Ho, Er, Tm, Yb, Lu, or Y) and hexagonal structures belong to a class of materials known as hexagonal ferroelectrics, in contrast to those with large rare earths and orthorhombic, perovskite-related structures showing different physical properties. In this work, we study the effects of growth conditions on the stabilization of HoMnO 3 films with both hexagonal and orthorhombic structures. Based on our experimental results, a HoMnO 3 film with a hexagonal structure can be stabilized on Si(111) at 850 C and above. Pure orthorhombic phases grow on SrTiO 3 (100), SrTiO 3 (110), LaAlO 3 (100), and LaAlO 3 (110) in a temperature range from 750 to 850 C. Multiphase samples can be grown on MgO(100) at all temperatures. #

Angular dependence of the magnetoelectric effect in orthorhombic HoMnO3films

“…Hexagonal and orthorhombic manganites have attracted tremendous research interest, since these systems often show a strong coupling between electric and magnetic degrees of freedom. [1][2][3][4] Of interest for the growth of heterostructures and superlattices are the orthorhombic phases, [5][6][7][8][9] since these can be combined with other ferromagnetic and ferroelectric perovskites such as SrRuO 3 , La 0.7 Sr 0.3 MnO 3 , and BaTiO 3 . Orthorhombic HoMnO 3 crystallizes in the GdFeO 3 -type structure (Pbnm).…”