Hutsune erako Akatsen Azterketa Ni-Mn-Z (Z = Ga, Sn, In) Aleazioetan

Abstract

Positroi-deuseztapen bizidenboren espektroskopiaren bidez eta positroi-bizidenboren kalkulu teorikoen bitartez,Ni50Mn50−xSnx (x = 25, 20, 15, 13, 10) eta Ni50Mn50−xInx (x = 25, 20, 16, 13) aleazioen hutsune erako akatsakaztertu dira. Ni2MnGa aleazioan aurretiaz burutu diren ikerketez baliatuz, akats-motaren zehaztapena Ni2MnGalaginera hedatu da ere. Elektroi-positroi kalkuluen emaitzak eta esperimentalki neurtutako emaitzak alderatuz,aztertutako aleazioetan agertzen den hutsune erako akatsa VNi dela frogatzen da.Bestalde, elektroi-positroikalkulu zehatzak burutzeko erabili behar den hobekuntza-faktorearen bost parametrizazio ezberdin aztertu dira lanhonetan. Guzti horien artean emaitza esperimentalak hobekin aurresaten duena zehaztu da.Vacancy-type defects in Ni50Mn50−xSnx (x = 25, 20, 15, 13, 10) and Ni50Mn50−xInx (x = 25, 20, 16, 13) alloysare studied by theoretical PALS calculations and experimental measurements. Taking advantage of the existingPALS results for Ni-Mn-Ga systems, the study is extended also to this alloy. By combining the experimental resultsand electron-positron density functional calculations, VNi is identified as the most probable vacancy present in allthe studied systems. Moreover, the so-called enhancement factor, which acquires a key relevance for a properlifetime calculations, has been modeled by five different parametrizations, by which the parametrization that bestpredicts the experimental results is determined.