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1. Vertically aligned nanocomposite (BaTiO ₃ ) _0.8  : (La _0.7 Sr _0.3 MnO ₃ ) _0.2 thin films with anisotropic multifunctionalities

   https://doi.org/10.1039/D0NA00232A  

   Gao, Xingyao; Zhang, Di; Wang, Xuejing; Jian, Jie; He, Zihao; Dou, Hongyi; Wang, Haiyan (August 2020, Nanoscale Advances)

   null (Ed.)

   A new two-phase BaTiO 3  : La 0.7 Sr 0.3 MnO 3 nanocomposite system with a molar ratio of 8 : 2 has been grown on single crystal SrTiO 3 (001) substrates using a one-step pulsed laser deposition technique. Vertically aligned nanocomposite thin films with ultra-thin La 0.7 Sr 0.3 MnO 3 pillars embedded in the BaTiO 3 matrix have been obtained and the geometry of the pillars varies with deposition frequency. The room temperature multiferroic properties, including ferromagnetism and ferroelectricity, have been demonstrated. Anisotropic ferromagnetism and dielectric constants have been observed, which can be tuned by deposition frequencies. The tunable anisotropic optical properties originated from the conducting pillars in the dielectric matrix structure, which cause different electron transport paths. In addition, tunable band gaps have been discovered in the nanocomposites. This multiferroic and anisotropic system has shown its great potentials towards multiferroics and non-linear optics. 

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2. Exchange Bias in La _0.67 Sr _0.33 MnO ₃ /YFeO ₃ Ferromagnet/Antiferromagnet Multilayer Heterostructures

   https://doi.org/10.1002/smll.202501644  

   Fourmont, Paul; Cho, Eunsoo; Cloutier, Sylvain G; Ross, Caroline A (May 2025, Small)

   Abstract Exchange bias (EB), manifested as a hysteresis‐loop offset after field‐cooling, is demonstrated in perovskite‐structured ferromagnet/antiferromagnet (La_0.67Sr_0.33MnO₃/YFeO₃)_nheterostructures grown on (100) SrTiO₃substrates. Bilayer samples show an EB of 306 Oe at 50 K, whereas multilayers with five layers exhibit an exchange bias of up to 424 Oe at 50 K. A spin valve consisting of La_0.67Sr_0.33MnO₃/SrTiO₃/La_0.67Sr_0.33MnO₃/YFeO₃shows stable remanent configurations resulting from pinning of the upper La_0.67Sr_0.33MnO₃layer by the YFeO₃. In contrast, EB is not observed on (111)‐oriented SrTiO₃substrates due to interface roughening. These results demonstrate YFeO₃as an alternative orthoferrite antiferromagnet compared to BiFeO₃and LaFeO₃for incorporation into exchange‐biased heterostructures. 

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3. Strain- and thickness-dependent magnetic properties of epitaxial La _0.67 Sr _0.33 CoO ₃ /La _0.67 Sr _0.33 MnO ₃ bilayers

   https://doi.org/10.1063/5.0122009  

   Feng, Mingzhen; Ahlm, Nolan J.; Kane, Alexander M.; Chiu, I-Ting; Sasaki, Dayne Y.; Shafer, Padraic; N'Diaye, Alpha T.; Mehta, Apurva; Takamura, Yayoi (November 2022, Journal of Applied Physics)

   Magnetic properties and interfacial phenomena of epitaxial perovskite oxides depend sensitively on parameters such as film thickness and strain state. In this work, epitaxial La 0.67 Sr 0.33 CoO 3 (LSCO)/La 0.67 Sr 0.33 MnO 3 (LSMO) bilayers were grown on NdGaO 3 (NGO) and LaAlO 3 (LAO) substrates with a fixed LSMO thickness of 6 nm, and LSCO thickness (t LSCO ) varying from 2 to 10 nm. Soft x-ray magnetic spectroscopy revealed that magnetically active Co 2+ ions that strongly coupled to the LSMO layer were observed below a critical t LSCO for bilayers grown on both substrates. On LAO substrates, this critical thickness was 2 nm, above which the formation of Co 2+ ions was quickly suppressed leaving only a soft LSCO layer with mixed valence Co 3+ /Co 4+ ions. The magnetic properties of both LSCO and LSMO layers displayed strong t LSCO dependence. This critical t LSCO increased to 4 nm on NGO substrates, and the magnetic properties of only the LSCO layer displayed t LSCO dependence. A non-magnetic layer characterized by Co 3+ ions and with a thickness below 2 nm exists at the LSCO/substrate interface for both substrates. The results contribute to the understanding of interfacial exchange spring behavior needed for applications in next generation spintronic and magnetic memory devices. 

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4. Combinatorial Growth of Vertically Aligned Nanocomposite Thin Films for Accelerated Exploration in Composition Variation

   https://doi.org/10.1002/smsc.202300049  

   Rutherford, Bethany X.; Zhang, Di; Quigley, Lizabeth; Barnard, James P.; Yang, Bo; Lu, Juanjuan; Kunwar, Sundar; Dou, Hongyi; Shen, Jianan; Chen, Aiping; et al (September 2023, Small Science)

   Combinatorial growth is capable of creating a compositional gradient for thin film materials and thus has been adopted to explore composition variation mostly for metallic alloy thin films and some dopant concentrations for ceramic thin films. This study uses a combinatorial pulsed laser deposition method to successfully fabricate two‐phase oxide–oxide vertically aligned nanocomposite (VAN) thin films of La_0.7Sr_0.3MnO₃(LSMO)‐NiO with variable composition across the film area. The LSMO‐NiO compositional gradient across the film alters the two‐phase morphology of the VAN through varying nanopillar size and density. Additionally, the magnetic anisotropy and magnetoresistance properties of the nanocomposite thin films increase with increasing NiO composition. This demonstration of a combinatorial method for VAN growth can increase the efficiency of nanocomposite thin film research by allowing all possible compositions of thin film materials to be explored in a single deposition. 

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5. Role of Interlayer in 3D Vertically Aligned Nanocomposite Frameworks with Tunable Magnetotransport Properties

   https://doi.org/10.1002/admi.201901990  

   Sun, Xing; Kalaswad, Matias; Li, Qiang; Paldi, Robynne_L; Huang, Jijie; Wang, Han; Gao, Xingyao; Zhang, Xinghang; Wang, Haiyan (April 2020, Advanced Materials Interfaces)

   Abstract To investigate the role of interlayers on the growth, microstructure, and physical properties of 3D nanocomposite frameworks, a set of novel 3D vertically aligned nanocomposite (VAN) frameworks are assembled by a relatively thin interlayer (M) sandwiched by two consecutively grown La_0.7Sr_0.3MnO₃(LSMO)‐ZnO VANs layers. ZnO nanopillars from the two VAN layers and the interlayer (M) create a heterogeneous 3D frame embedded in the LSMO matrix. The interlayer (M) includes yttria‐stabilized zirconia (YSZ), CeO₂, SrTiO₃, BaTiO₃, and MgO with in‐plane matching distances increasing from ≈3.63 to ≈4.21 Å, and expected in‐plane strains ranging from tensile (≈8.81% on YSZ interlayer) to compressive (≈–6.23% on MgO interlayer). The metal‐insulator transition temperature increases from ≈133 K (M = YSZ) to ≈252 K (M = MgO), and the low‐field magnetoresistance peak value is tuned from ≈36.7% to ≈20.8%. The 3D heterogeneous frames empower excellent tunable magnetotransport properties and promising potentials for microstructure‐enabled applications. 

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