Membranesfor Multifunctional Heterogenous Integration*

Strongly correlated complex oxides are host to a spectrum of competing phases and physical properties[1,2]. Traditionally, single-crystalline films of complex oxides are obtained through epitaxial growth on compatible oxide substrates. However, this method is constrained by a narrow selection of material systems with similar lattice parameters. In the past few years, the engineering of freestanding oxide membranes, has openend new avenues towards versatile and readily transferable/integrable materials for heterointegation and new applications [3,4]. Yet, the synthesis, transfer, and integration of crack-free freestanding oxide membranes remains challenging [2]. In this work, we present our recent development on the fabrication of freestanding single-crystalline complex oxide membranes, La_0.7Sr_0.3MnO₃ (LSMO), by a chemical lift-off technique (e.g., emplng water-soluble Sr₃Al₂O₆ sacrificial layer). The details of releasing and transferring LSMO thin films will be discussed. The structural and magnetic properties of epitaxial and freestanding LSMO films were studied as a function of film thickness. Lastly, the relationship between the properties of the membranes and the fabrication process will be discussed.

References:

[1] R. Ramesh, & D. G. Schlom, MRS Bull. 33, 1006 (2008).

[2] H. Y. Hwang, et al., Nat. Mater. 11, 103 (2012).

[3] C. Francesco, et al., Annalen der Physik 534, 2200084(2022).

[4] Y. Li, et al., Adv. Mater. 34, 2203187 (2022).