TY - JOUR
T1 - Critical concentrations of Zn and Mg for enhanced diamagnetism in Al-Zn-Mg alloys
AU - Nishimura, Katsuhiko
AU - Matsuda, Kenji
AU - Tsuchiya, Taiki
AU - Nunomura, Norio
AU - Bendo, Artenis
AU - Isikawa, Yosikazu
AU - Imai, Kosuke
AU - Adachi, Hiroki
AU - Hutchison, Wayne D.
N1 - Publisher Copyright:
© 2019 Author(s).
PY - 2019/12/1
Y1 - 2019/12/1
N2 - Temperature and time dependences of the magnetization of Al-Zn-Mg alloys with varying Zn to Mg ratios (Zn/Mg = 0.25, 0.5, 1, 2, 5.5, and 9, keeping the total concentration of Zn plus Mg to be 5 at. %) were studied in the range from 10 to 310 K after various periods of natural aging. In particular, for Al1-y(Mg2Zn11)y alloys, the total concentrations of Zn and Mg were also varied from 2 to 20 at. % (y = 0.02, 0.03, 0.04, 0.05, 0.1, and 0.2). The largest time variant enhanced diamagnetism was observed for Al0.95(Mg2Zn11)0.05 as a result of solution heat treatment/quenching and natural aging. Isothermal measurements of magnetization vs time for natural aging temperatures from 260 to 300 K for Al0.95(Mg2Zn11)0.05 provided activation energies for solute clustering: 0.69 ± 0.05 eV (for stages I and II) and 0.78 ± 0.03 eV (for stages II and III). The mechanical hardness vs time at 273 K for Al0.95(Mg2Zn11)0.05 confirmed that the time variation of magnetization was related to the precipitation process of Zn/Mg/vacancy zones. Additionally, temperature dependences of the magnetization of Mg21Zn25, Mg4Zn7, MgZn2, and Mg2Zn11 were examined. The observed magnetization for the Mg-Zn compounds was found to be too small to account for the enhanced diamagnetic contributions to magnetization of Al-Zn-Mg alloys. A possible Zn-Mg-vacancy atomic arrangement responsible for the enhanced diamagnetism is discussed.
AB - Temperature and time dependences of the magnetization of Al-Zn-Mg alloys with varying Zn to Mg ratios (Zn/Mg = 0.25, 0.5, 1, 2, 5.5, and 9, keeping the total concentration of Zn plus Mg to be 5 at. %) were studied in the range from 10 to 310 K after various periods of natural aging. In particular, for Al1-y(Mg2Zn11)y alloys, the total concentrations of Zn and Mg were also varied from 2 to 20 at. % (y = 0.02, 0.03, 0.04, 0.05, 0.1, and 0.2). The largest time variant enhanced diamagnetism was observed for Al0.95(Mg2Zn11)0.05 as a result of solution heat treatment/quenching and natural aging. Isothermal measurements of magnetization vs time for natural aging temperatures from 260 to 300 K for Al0.95(Mg2Zn11)0.05 provided activation energies for solute clustering: 0.69 ± 0.05 eV (for stages I and II) and 0.78 ± 0.03 eV (for stages II and III). The mechanical hardness vs time at 273 K for Al0.95(Mg2Zn11)0.05 confirmed that the time variation of magnetization was related to the precipitation process of Zn/Mg/vacancy zones. Additionally, temperature dependences of the magnetization of Mg21Zn25, Mg4Zn7, MgZn2, and Mg2Zn11 were examined. The observed magnetization for the Mg-Zn compounds was found to be too small to account for the enhanced diamagnetic contributions to magnetization of Al-Zn-Mg alloys. A possible Zn-Mg-vacancy atomic arrangement responsible for the enhanced diamagnetism is discussed.
UR - http://www.scopus.com/inward/record.url?scp=85076590485&partnerID=8YFLogxK
U2 - 10.1063/1.5126972
DO - 10.1063/1.5126972
M3 - 学術論文
AN - SCOPUS:85076590485
SN - 2158-3226
VL - 9
JO - AIP Advances
JF - AIP Advances
IS - 12
M1 - 125111
ER -