Radiation-induced disordering in magnesium aluminate spinel subjected to ionizing radiation

The atomic structure of disordered ion tracks in magnesium aluminate spinel

“…[10][11][12][13] Special attention is placed on the correlation of the microstructure and disordering at and around ion tracks. Transmission-electron microscopy (TEM) techniques such as high-resolution (HR) and bright-fi eld (BF) imaging, and high angular resolution electron channeling spectroscopy (HARECXS) analysis were utilized to investigate ion tracks induced by 200 MeV xenon and 350 MeV gold ions.…”

Frenkel pair accumulation induced crystallization of amorphous MgAl2O4

“…Radiation-induced behavior has been studied extensively using both experimental techniques [2][3][4][5][6] and recently numerous atomic scale modeling [7,8]. It has been observed that the amorphous (A) state may re-crystallize into a defective rock salt (NaCl) structure under electron irradiation [9].…”

Production and stability of radiation-induced defects in MgAl2O4 under electronic excitation

“…We have investigated the structure and ion configuration of ion tracks using coupling TEM techniques, and examined the detailed structure of ion tracks induced by 200 MeV Xe and 350 MeV Au ions [15,16,18]. Ion tracks observed with a plan view specimen of MgO Á 1.1Al 2 O 3 , whose composition is slightly deviated from stoichiometry, showed that the inside of the tracks retain spinel structure, whereas cations at the core region of ion tracks induced by 350 MeV Au ions ((dE/dx) e = 35 keV/nm) preferentially migrate from tetrahedral IV sites to octahedral VI sites suggesting the formation of defective rock-salt structure at the core region [18].…”

“…Individual ion tracks are shown to remain crystalline up to (dE/dx) e = 40 keV/nm [13], although overlapping of multiple ion tracks (around 10 20 ions/m 2 ) induces amorphization [13]. X-ray diffraction [17] and electron channelling [15,16,18] analyses have detected that a high density of electronic excitation also causes significant cation disordering along ion tracks. A preferential migration of cations from tetrahedral to octahedral sites, which has been discussed as a trigger to amorophization, is also revealed at (dE/dx) e = 35 keV/nm [18].…”

“…High density electronic excitation induced by swift heavy ions is known to create ion tracks in MgAl 2 O 4 [12][13][14][15][16]. Previous investigations have found that continuous ion tracks are formed if the value of (dE/dx) e is higher than $8 keV/nm [12].…”