Rare-earth solid-state NMR spectroscopy of intermetallic compounds: The case of the Lu-175 isotope

Author(s)

Benndorf, Christopher ^{[1, 2]} ; de Oliveira Junior, Marcos ^[3] ; Bradtmueller, Henrik ^[4] ; Stegemann, Frank ^[1] ; Poettgen, Rainer ^[1] ; Eckert, Hellmut ^{[4, 3]}

Affiliation

^[1] Westfalische Wilhelms Univ Munster, Inst Anorgan & Analyt Chem, Corrensstr 30, D-48149 Munster - Germany

^[2] Univ Leipzig, Inst Mineral Kristallog & Mat Wissensch, Schamhorststr 20, D-04275 Leipzig - Germany

^[3] Univ Sao Paulo, Inst Fis Sao Carlos, CEP 369, BR-13566590 Sao Carlos, SP - Brazil

^[4] Westfalische Wilhelms Univ Munster, Inst Phys Chem, Corrensstr 30, D-48149 Munster - Germany

• Document type: Journal article
• Source: SOLID STATE NUCLEAR MAGNETIC RESONANCE; v. 101, p. 63-67, SEP 2019.
• Web of Science Citations: 1

Abstract

The feasibility of high-resolution Lu-175 solid-state NMR spectroscopy in intermetallic compounds crystallizing with cubic crystal structures is explored by magic-angle spinning NMR at different magnetic flux densities. The large quadrupole moment of this isotope (3.49 x 10(-28) m(2)) restricts observation of the NMR signal to nearly perfectly ordered crystalline samples. Signals are successfully detected and analyzed in the binary pnictides LuPn (NaCl-type structure; Pn = P, As, Sb) and the intermetallic compounds LuPtSb and LuAuSn, both crystallizing with the MgAgAs-type structure. Sources of line broadening are discussed based on field-dependent static and MAS-NMR spectra, providing guidance with respect to measurement conditions resulting in reliable results. The results highlight the importance of ionic/ covalent bonding effects for the detectability of the signal, which reduce the probability of real structure effects commonly observed in intermetallic compounds. No Lu-175 NMR signals can be observed in various cubic Heusler compounds. This is attributed to mixed site occupancies and other structural defects producing electric field gradients whose interaction with the Lu-175 quadrupole moments broadens the signal beyond detection. (AU)

• FAPESP's process: 13/07793-6 - CEPIV - Center for Teaching, Research and Innovation in Glass
• Grantee: Edgar Dutra Zanotto
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC
• FAPESP's process: 13/23490-3 - Magnetic Resonance Techniques for the Study of Structure/Property Correlations in Photonic Glassy and Glass Ceramic Materials
• Grantee: Marcos de Oliveira Junior
• Support Opportunities: Scholarships in Brazil - Post-Doctoral