Bulletin of the American Physical Society
APS March Meeting 2023
Volume 68, Number 3
Las Vegas, Nevada (March 5-10)
Virtual (March 20-22); Time Zone: Pacific Time
Session RR01: V: Multiferroics and Ferroelectrics II |
Hide Abstracts |
Sponsoring Units: DMP Chair: Lun Jin, Princeton University Room: Virtual Room 1 |
Tuesday, March 21, 2023 11:30AM - 11:42AM |
RR01.00001: A study on polarization switching in hybrid improper ferroelectric double perovskites oxides from first principles computations and machine learning Gayathri Palanichamy, Ayana Ghosh, Saurabh Ghosh ABO3 perovskite oxides with Pnma symmetry exhibit polarization via hybrid improper ferroelectric mechanism (HIF). Here the primary order parameters are rotation (QR+) and tilt (QT) distortions along a0a0c+ and a-a-c0, respectively. Naturally, it has been believed that functionalities such as polarization can also be switched by tuning these primary order parameters. In this study, we have identified a unique low-energy polarization switching path via out-of-phase rotation QR- for a series of polar double perovskite oxides (DPOs). Finite temperature simulations using ab initio molecular dynamics (AIMD) are performed to outline the design rules of temperature-dependent ultra-fast polarization switching. Later, we constructed a wide compositional space with various combinations of 3d-3d, 3d-4d, and 3d-5d elements to construct machine learning (ML) models. The ML models use the understandings gained from the representative simulations performed on a handful DPOs. This presentation will focus on discussing these results particularly targeted at designing DPOs with low switching barriers and high polarization. |
Tuesday, March 21, 2023 11:42AM - 11:54AM |
RR01.00002: Strongly stabilized magnetic phase transitions in vdW multiferroic NiI2 under hydrostatic pressure Luiz Gustavo Pimenta Martins, Connor A Occhialini, Qian Song, Jesse S Smith, Joshua J Sanchez, Jesse Kapeghian, Danila Amoroso, Antia S Botana, Matthieu J Verstraete, Jing Kong, Riccardo Comin Multiferroics with coupled ferroelectric and magnetic orders have been the subject of intense interest for their functional magnetoelectric properties. The van der Waals (vdW) material NiI2 has emerged as a new platform to explore multiferroicity in the 2D limit, enabling a plethora of potentially new physical phenomena due to reduced dimensionality. In this case, frustration of intralayer exchange interactions on the triangular magnetic lattice results in two magnetic phase transitions, first to an antiferromagnetic state at TN1 = 75K and then to an incommensurate, helimagnetic and multiferroic phase at TN2 = 60 K. These critical temperatures decrease with decreasing number of layers, revealing the importance of interlayer exchange interactions to stabilize the helimagnetism. In this vein, hydrostatic pressure is a powerful tool that can be used to tune the interlayer distance in vdW materials and, hence, enhance the interlayer exchange, as well as to perturb the delicate balance of intralayer exchange interactions which result in non-collinear magnetism. Here we investigate the magnetic and structural phase transitions in bulk NiI2 with high-pressure temperature-dependent (30K-298K) Raman spectroscopy, optical linear dichroism (LD) and x-ray diffraction (XRD). We obtain evidence for a significant and concurrent enhancement of both the magnetic (TN1) and multiferroic (TN2) transitions at a rate of ~ 14K/GPa. Our results reveal a general path to obtain high-temperature type-II multiferroicity via high pressures in vdW materials, allowing for a deeper understanding of the role of the intra- and inter-layer exchange parameters to guide the design of novel multiferroic vdW materials. |
Tuesday, March 21, 2023 11:54AM - 12:06PM |
RR01.00003: Inverse band gap versus polarization relation in ferroelectrics from first principles Sebastian E Reyes-Lillo, Nicolas Forero, Nicolas Varas New pathways to design functional ferroelectrics are desired for electro-optic and solar energy conversion devices. Previous work has focussed on searching ferroelectrics with small band gaps in the visible solar spectrum. In this work, we take an alternative route, and use first principles methods and the modern theory of polarization to perform a high-throughput search of ferroelectrics that display an inverse relation between electronic band gap and polarization, such that the band gap decreases as the polarization increases with an external parameter. To our knowledge, such material property has not been reported before, and we propose it as a new way to design small band gap ferroelectrics. We start by studying a list of 200 materials previously reported as a ferroelectrics database, and later generalize our search to identify new ferroelectrics with inverse band gap versus polarization relation within the Materials Project database. We have found 21 ferroelectrics with the proposed property among different families of ferroelectric materials and use hydrostatic strain as an external parameter to explore their band gap and polarization relation. This work is supported by ANID Fondecyt Regular 1220986. |
Tuesday, March 21, 2023 12:06PM - 12:18PM |
RR01.00004: Intrinsic Orbital Magnetoelectric Effect at finite temperature with the Kubo formula Koki Shinada, Akira Kofuji, Robert Peters Orbital magnetization (OM) is a fundamental quantity along with spin etc., however there is a theoretical difficulty from the ill-definedness of positional operator in periodic systems. In equilibrium, this difficulty is circumvented by a thermodynamic formulation, which can be applied even at finite temperature. On the other hand, quantum mechanical formalizations of the OM under external feilds such as electric field at finite temperature are ongoing problem. |
Tuesday, March 21, 2023 12:18PM - 12:30PM |
RR01.00005: The sliding phase transition in ferroelectric van der Waals bilayers Ping Tang, Gerrit E W Bauer The discovery of ferroelectricity in van der Waals-stacked bilayers with out-of-plane polarization substantially expands the family of ferroelectric materials and has triggered tremendous interest. The unconventional dipolar order arises from the locking of the sliding motion of weakly coupled monolayers and ultralow potential barrier for switching (~meV per unit cell). Surprisingly, despite the extremely low barrier such “sliding ferroelectricity” can be stable above room temperature. In contrast, the order of two-dimensional van der Waals ferromagnets rarely survive at elevated temperatures. Here we present a theoretical picture that explains the conundrum of sliding ferroelectricity and the modelling of various associated observables. We attribute the robustness of the ferroelectricity recently observed in h-BN and WTe2 bilayers to large monolayer in-plane stiffness. A soft “sliding phonon” of the bilayers triggers the phase transition at high Curie temperatures as an interplay between switching barrier and intralayer elasticity. This mechanism also holds for structural phase transitions in non-ferroelectric bilayers for which we predict anomalies of the specific heat at the critical temperature. |
Tuesday, March 21, 2023 12:30PM - 12:42PM |
RR01.00006: Hallmarks of electric and magnetic multipole orders in the band structure of variations of diamond and lonsdaleite Roland Winkler, Uli Zülicke We have developed a comprehensive theoretical framework for electric and magnetic multipole order in compounds with crystal structures belonging to the diamond and lonsdaleite families. Both group-theoretical and microscopic tight-binding methods are employed to study the electronic band structure and identify key features enabled by symmetry-lowering electric and magnetic multipoles. Juxtaposing the effects of electric and magnetic multipoles of the same order, we establish dualities between crystal symmetries and their observable signatures. Our investigation points the way for how to systematically realize electric and magnetic multipole order under the umbrella of the diamond and lonsdaleite materials classes and it provides a rational structure for the range of currently known types of spin splittings (Rashba, Dresselhaus, Zeeman, AFM-induced, ...) that may arise due to these multipoles. We also clarify the conditions under which axial- and polar-toroidal order emerges within this material platform. |
Tuesday, March 21, 2023 12:42PM - 12:54PM |
RR01.00007: Role of magnetization parameters in designing high-performance spin-driven thermoelectrics Morteza Jazandari, Jahanfar Abouie, Daryoosh Vashaee Magnetic short-range order above the ordering temperature in some magnetic semiconductors, |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700