B-11 and Y-89 solid state MAS NMR spectroscopic investigations of the layered borides YTB4 (T = Mo, W, Re)

Autor(es)

Benndorf, Christopher ^{[1, 2, 3]} ; de Oliveira, Marcos ^[4] ; Doerenkamp, Carsten ^[4] ; Haarmann, Frank ^{[5, 6]} ; Fickenscher, Thomas ^[2] ; Koesters, Jutta ^[2] ; Eckert, Hellmut ^{[1, 4]} ; Poettgen, Rainer ^[2]

Afiliação do(s) autor(es)

^[1] Univ Munster, Inst Phys Chem, Corrensstr 30, D-48149 Munster - Germany

^[2] Univ Munster, Inst Anorgan & Analyt Chem, Corrensstr 30, D-48149 Munster - Germany

^[3] Univ Leipzig, Inst Mineral Kristallog & Mat Wissensch, Scharnhorststr 20, D-04275 Leipzig - Germany

^[4] Univ Sao Paulo, Inst Phys Sao Carlos, BR-13560590 Sao Carlos, SP - Brazil

^[5] Rhein Westfal TH Aachen, Inst Anorgan Chem, Landoltweg 1, D-52074 Aachen - Germany

^[6] Max Planck Inst Chem Phys Fester Stoffe, Nothnitzer Str 40, D-01187 Dresden - Germany

• Tipo de documento: Artigo Científico
• Fonte: DALTON TRANSACTIONS; v. 48, n. 3, p. 1118-1128, JAN 21 2019.
• Citações Web of Science: 0

Resumo

The YCrB4 type borides YTB4 (T = Mo, W, Re) were synthesized from the elements by arc-melting and subsequent annealing. The structures were refined from single crystal X-ray diffractometer data: Pbam, a = 602.84(8), b = 1164.5(1), c = 361.20(4) pm, wR(2) = 0.0404, 624 F-2 values, 26 variables for YMoB4, a = 603.00(7), b = 1165.1(1), c = 360.63(6) pm, wR(2) = 0.0487, 474 F-2 values, 26 variables for YWB4, and a = 596.67(6), b = 1154.4(1), c = 360.21(4) pm, wR(2) = 0.0465, 544 F-2 values, 26 variables for YReB4. The boron atoms build up planar networks which are a tessellation of slightly distorted pentagons and heptagons. Adjacent networks coordinate the transition metal and yttrium atoms in the form of pentagonal and heptagonal prisms, respectively. The four crystallographically distinct boron sites are differentiated by high-resolution B-11 solid state isotropic magnetic shifts and nuclear electric quadrupolar coupling constants. Partial site assignments are possible based on comparisons with electric field gradient calculations using the WIEN2k code. Y-89 MAS NMR spectroscopic studies suggest substantially weaker Knight shift contributions to the resonance frequencies when compared to other intermetallic yttrium compounds, including other ternary yttrium boride compounds measured previously. (AU)

• Processo FAPESP: 17/06649-0 - Novos materiais óticos baseados em vidros e cerâmicas oxifluoretos dopados com terras-raras: estudos estruturais por ressonância paramagnética eletrônica.
• Beneficiário: Carsten Doerenkamp
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 13/23490-3 - Técnicas de ressonância magnética empregadas no estudo da correlação estrutura/propriedades em vidros e vitrocerâmicas fotônicos
• Beneficiário: Marcos de Oliveira Junior
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado