TY - JOUR
T1 - Evolution of magnetic properties in the normal spinel solid solution Mg 1xCu xCr 2O 4
AU - Kemei, Moureen C.
AU - Moffitt, Stephanie L.
AU - Shoemaker, Daniel P.
AU - Seshadri, Ram
PY - 2012/2/1
Y1 - 2012/2/1
N2 - We examine the evolution of magnetic properties in the normal spinel oxides Mg 1xCu xCr 2O 4 using magnetization and heat capacity measurements. The end-member compounds of the solid solution series have been studied in some detail because of their very interesting magnetic behavior. MgCr 2O 4 is a highly frustrated system that undergoes a first-order structural transition at its antiferromagnetic ordering temperature. CuCr 2O 4 is tetragonal at room temperature as a result of JahnTeller active tetrahedral Cu 2+ and undergoes a magnetic transition at 135K. Substitution of magnetic cations for diamagnetic Mg 2+ on the tetrahedral A site in the compositional series Mg 1xCu xCr 2O 4 dramatically affects magnetic behavior. In the composition range 0x0.3, the compounds are antiferromagnetic. A sharp peak observed at 12.5K in the heat capacity of MgCr 2O 4 corresponding to a magnetically driven first-order structural transition is suppressed even for small x. Uncompensated magnetismwith open magnetization loopsdevelops for samples in the x range 0.43x1. Multiple magnetic ordering temperatures and large coercive fields emerge in the intermediate composition range 0.43x0.47. The Néel temperature increases with increasing x across the series while the value of the CurieWeiss CW decreases. A magnetic temperaturecomposition phase diagram of the solid solution series is presented.
AB - We examine the evolution of magnetic properties in the normal spinel oxides Mg 1xCu xCr 2O 4 using magnetization and heat capacity measurements. The end-member compounds of the solid solution series have been studied in some detail because of their very interesting magnetic behavior. MgCr 2O 4 is a highly frustrated system that undergoes a first-order structural transition at its antiferromagnetic ordering temperature. CuCr 2O 4 is tetragonal at room temperature as a result of JahnTeller active tetrahedral Cu 2+ and undergoes a magnetic transition at 135K. Substitution of magnetic cations for diamagnetic Mg 2+ on the tetrahedral A site in the compositional series Mg 1xCu xCr 2O 4 dramatically affects magnetic behavior. In the composition range 0x0.3, the compounds are antiferromagnetic. A sharp peak observed at 12.5K in the heat capacity of MgCr 2O 4 corresponding to a magnetically driven first-order structural transition is suppressed even for small x. Uncompensated magnetismwith open magnetization loopsdevelops for samples in the x range 0.43x1. Multiple magnetic ordering temperatures and large coercive fields emerge in the intermediate composition range 0.43x0.47. The Néel temperature increases with increasing x across the series while the value of the CurieWeiss CW decreases. A magnetic temperaturecomposition phase diagram of the solid solution series is presented.
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U2 - 10.1088/0953-8984/24/4/046003
DO - 10.1088/0953-8984/24/4/046003
M3 - Article
C2 - 22223597
AN - SCOPUS:84855682149
VL - 24
JO - Journal of Physics Condensed Matter
JF - Journal of Physics Condensed Matter
SN - 0953-8984
IS - 4
M1 - 046003
ER -