Cryogenic Focused Ion Beam Milling to Investigate the Anisotropic Magnetotransport Properties of Bismuth Microcrystals

Sáenz-Hernández, Amaia ; Sangiao, Soraya (Universidad de Zaragoza) ; Felser, Claudia ; Shekhar, Chandra ; Pardo, José Ángel (Universidad de Zaragoza) ; Ibarra, Alfonso ; De Teresa, José María

Resumen: Bulk single crystals exhibit the intrinsic properties of a given compound, but studying their anisotropic magnetotransport properties is challenging. Focused Ion Beam (FIB) milling at room temperature has been previously used to guide the electrical current path along a defined crystal direction or to extract microcrystals where the electrical current flows along a known direction. However, some materials, such as bismuth, melt under FIB irradiation. Bismuth, known for its unique properties, including very large magnetoresistance and a highly anisotropic Fermi surface, reacts to room‐temperature Ga+ FIB irradiation, forming droplets on its surface. Therefore, a novel microfabrication approach based on cryogenic FIB milling is developed here. By using a Peltier stage or an integrated cryogenic module, surface melting is mitigated below −30 °C. Microscale slabs are extracted, either parallel or perpendicular to the single crystal surface, then shaped and electrically contacted in a chip for magnetotransport characterization. The large magnetoresistance observed along with Shubnikov–de Haas oscillations with single periodicity when current is applied perpendicular to the c axis, highlights the success of the approach. These results enable FIB microfabrication of single crystals that are sensitive to FIB irradiation and investigation of the anisotropic magnetotransport properties in microcrystals.

Idioma: Inglés

DOI: 10.1002/adfm.202517475

Año: 2025

Publicado en: Advanced Functional Materials (2025), e17475 [10 pp.]
ISSN: 1616-301X

Financiación: info:eu-repo/grantAgreement/ES/AEI/PID2023-146451OB-I00
Financiación: info:eu-repo/grantAgreement/ES/DGA/E13-23R
Financiación: info:eu-repo/grantAgreement/ES/MICINN-AEI/PID2020-112914RB-I00
Financiación: info:eu-repo/grantAgreement/ES/MICINN/CEX2021-001144-S-20–9
Financiación: info:eu-repo/grantAgreement/ES/MICINN PRE2022-103314
Financiación: info:eu-repo/grantAgreement/ES/MICIU/CEX2023-001286-S

Tipo y forma: Article (Published version)

Área (Departamento): Área Física Materia Condensada (Dpto. Física Materia Condensa.)
Área (Departamento): Área Cienc.Mater. Ingen.Metal. (Dpto. Ciencia Tecnol.Mater.Fl.)