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Updated: May 26, 2026
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Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
Published on: June 7, 2018
Evolution of magnetic properties in the normal spinel solid solution Mg(1-x)Cu(x)Cr2O4
Moureen C Kemei1, Stephanie L Moffitt, Daniel P Shoemaker
1Materials Department, University of California, Santa Barbara, CA 93106, USA. kemei@mrl.ucsb.edu
Summary
The magnetic properties of Mg(1-x)Cu(x)Cr2O4 spinels change significantly with copper substitution. Antiferromagnetism transitions to uncompensated magnetism, altering ordering temperatures and structural stability.
Area of Science:
- Materials Science
- Solid State Physics
- Magnetism
Background:
- Normal spinel oxides Mg(1-x)Cu(x)Cr2O4 exhibit complex magnetic behaviors.
- MgCr2O4 shows magnetic frustration and a first-order structural transition.
- CuCr2O4 possesses Jahn-Teller active Cu2+ and a magnetic transition at 135 K.
Purpose of the Study:
- To investigate the evolution of magnetic properties in Mg(1-x)Cu(x)Cr2O4 solid solutions.
- To understand how copper substitution influences magnetic ordering and structural transitions.
- To map the magnetic phase diagram of the Mg(1-x)Cu(x)Cr2O4 system.
Main Methods:
- Magnetization measurements were performed across the solid solution series.
- Heat capacity measurements were used to identify phase transitions.
- Analysis of magnetic ordering temperatures and structural transitions was conducted.
Main Results:
- Antiferromagnetism is observed for 0 ≤ x ≤ ≈0.3.
- A magnetically driven structural transition in MgCr2O4 is suppressed with small x.
- Uncompensated magnetism with open hysteresis loops develops for x ≈0.43–1.
- Intermediate compositions (0.43 ≤ x ≤ 0.47) show multiple ordering temperatures and large coercive fields.
- Néel temperature increases with x, while Curie-Weiss temperature decreases.
Conclusions:
- Copper substitution dramatically alters the magnetic behavior of MgCr2O4.
- A complex magnetic phase diagram emerges with increasing copper content.
- The interplay between magnetic ordering and structural transitions is composition-dependent.
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