TY - JOUR

T1 - Aluminothermic Synthesis of Dispersed Electrides Based on Mayenite: XRD and EPR Study

AU - Володин, Александр Михайлович

AU - Кенжин, Роман Мугарамович

AU - Капишников, Александр Владимирович

AU - Комаровских, Андрей

AU - Ведягин, Алексей Анатольевич

N1 - This work was supported by the Ministry of Science and Higher Education of the Russian Federation [projects No. 121031700313–8 and AAAA-A21-121011390054-1].

PY - 2022/12/16

Y1 - 2022/12/16

N2 - The evolution of the structure and the phase composition of a dispersed mayenite at its interaction with metallic aluminum was studied in a temperature range from 900 to 1400 °C in both argon and air atmospheres. The aluminum loading was varied from 0 to 50 wt%. It was found that the addition of aluminum significantly affects the stability of the mayenite and other calcium aluminate phases within the studied temperature range. The formation of the electride state registered by the appearance of a characteristic electron paramagnetic resonance (EPR) signal from F+-like centers (g~1.994) in an argon atmosphere was shown to take place already at 1150 °C due to an aluminothermic reduction of this material. The super-narrow (Hp-p < 0.5 G) EPR spectra from F+-like centers, which were recently observed for the core-shell structures of the C12A7@C type only, were registered for mayenite for the first time. The results obtained in the present study testify firstly towards the possibility of significantly diminishing the temperatures required for the formation of the electride state in such systems and secondly towards the ability to stabilize the size of small electride nanoparticles within the synthesized calcium aluminate matrix.

AB - The evolution of the structure and the phase composition of a dispersed mayenite at its interaction with metallic aluminum was studied in a temperature range from 900 to 1400 °C in both argon and air atmospheres. The aluminum loading was varied from 0 to 50 wt%. It was found that the addition of aluminum significantly affects the stability of the mayenite and other calcium aluminate phases within the studied temperature range. The formation of the electride state registered by the appearance of a characteristic electron paramagnetic resonance (EPR) signal from F+-like centers (g~1.994) in an argon atmosphere was shown to take place already at 1150 °C due to an aluminothermic reduction of this material. The super-narrow (Hp-p < 0.5 G) EPR spectra from F+-like centers, which were recently observed for the core-shell structures of the C12A7@C type only, were registered for mayenite for the first time. The results obtained in the present study testify firstly towards the possibility of significantly diminishing the temperatures required for the formation of the electride state in such systems and secondly towards the ability to stabilize the size of small electride nanoparticles within the synthesized calcium aluminate matrix.

KW - EPR

KW - XRD

KW - aluminothermic reduction

KW - calcium aluminate

KW - mayenite structure

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85144613668&origin=inward&txGid=4d1c95537cecdee44c48061216e30985

UR - https://www.mendeley.com/catalogue/8fed5013-8b30-3bd6-a5d8-6b900787a78a/

U2 - 10.3390/ma15248988

DO - 10.3390/ma15248988

M3 - Article

C2 - 36556802

VL - 15

JO - Materials

JF - Materials

SN - 1996-1944

IS - 24

M1 - 8988

ER -