Novel magnetoelectric composites for energy-efficient memory concepts based on CMOS compatible ferroelectrics

The rapid expansion of information technologies has intensified global energy demands, especially in data storage and processing. Conventional magnetic devices rely on current-driven switching, leading to Joule heating and power losses. Magnetoelectric (ME) composites enable electric-field control of magnetization, offering a route to low-power electronics.

Single-phase ME materials intrinsically couple polarization and magnetization, but their effects are weak and usually limited to low temperatures. Composite ME heterostructures overcome these limitations by combining distinct ferroic orders, enabling strong room-temperature coupling through strain-, charge- or ion-transfer mechanisms. However, state-of-the-art ME composites often rely on high-performance ferroelectrics/piezoelectrics such as PZT or BaTiO₃, which pose challenges for CMOS integration due to high processing temperatures and/or inclusion of toxic elements. Recently developed lead-free, low-temperature ferroelectrics such as HfO₂ and ZrO₂-based thin films, or Sc-doped AlN and Mg-doped ZnO offer a promising alternative. They retain robust ferroic properties at the nanoscale while enabling voltage-controlled ME effects in silicon-compatible devices.

While the ferroelectric properties of HfO₂ and Sc-doped AlN are well known, their integration into voltage-controlled ME heterostructures for advanced energy-efficient memory concepts remains largely unexplored. This PhD project aims to design, fabricate, and characterize CMOS-compatible ME heterostructures using lead-free ferroelectrics. The work will involve carefully designed experiments to disentangle different magnetoelectric coupling mechanisms, including employing dopants to tune the ionic character and exploring ferroelectrics with varying piezoelectric coefficients. A comprehensive set of structural, compositional, electrical and magnetic characterization techniques, complemented by experiments at large-scale (e.g. synchrotron) facilities when needed.

The candidate should have a strong background in materials science, solid-state physics, or a related field, preferably with foundational knowledge of ferroic materials, magnetism, and thin-film concepts. Practical experience or a strong interest in thin-film deposition and materials characterization (structural, magnetic, and electrical) will be advantageous, supporting the development of magnetoelectric expertise during the course of the PhD. The candidate must be curious, adaptable, collaborative, and possess strong problem-solving skills, since the project involves designing and testing sophisticated materials beyond the state of the art. Proficiency in data analysis, basic modelling, and scientific communication will be essential for interpreting results, troubleshooting experiments, and disseminating findings through publications and presentations. Initiative, independent learning, and teamwork are key to success in this interdisciplinary research environment.

This project brings together two research groups: Gnm³ at the Department of Physics of the Universitat Autònoma de Barcelona and FOXEM at the Institut de Ciència de Materials de Barcelona, combining expertise in the electrical and magnetic properties of materials to drive innovation from thin films to nanostructures. Gnm3 focuses on the design, synthesis and characterization of advanced materials with controlled nanoscale architectures and has developed strong know-how in magnetoelectric phenomena. FOXEM develops high-quality ferroelectric oxide films compatible with industry, advancing epitaxial growth, structural and electrical characterization. The combination of Gnm3’s expertise in magnetoelectric with FOXEM’s specialization in ferroelectrics provides a synergy already demonstrated, bridging fundamental design with functional implementation to establish a multidisciplinary framework for next-generation devices in energy, memory and communication technologies.