Fractionation as a Tool to Control Mn/Al Site Mixing and Magnetism in CaMn_{2+x}Al_{10-x}
Abstract
We report single crystal growth and physical property characterization of CaMn_{2+x}Al_{10-x} crystals grown using a fractionation approach. Three consecutive batches were obtained from the same initial melt composition, systematically sampling neighboring, narrow regions of the ternary Ca-Mn-Al phase diagram. Single-crystal X-ray diffraction measurements reveal Mn/Al site mixing, with the excess Mn concentration, x, decreasing systematically with decreasing decanting temperature. A low-temperature upturn in magnetization and a maximum in electrical resistivity both become progressively weaker with decreasing excess Mn content, suggesting that the previously reported magnetic properties attributed to stoichiometric CaMn_{2}Al_{10} instead arise from an inhomogeneous distribution of excess Mn atoms. More broadly, the results presented in this work demonstrate how fractionation can help distinguish intrinsic magnetic behavior from disorder-induced effects associated with an inhomogeneous distribution of magnetic ions in materials with a finite width of formation, particularly when itinerant magnetism is under consideration.
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BibTeX
@misc{krolak2026fractionation,
title = {{Fractionation as a Tool to Control Mn/Al Site Mixing and Magnetism in CaMn_2+xAl_10-x}},
author = {Szymon Królak and Sushma Kumari and Sergey L. Bud'ko and Paul C. Canfield},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.27391},
eprint = {2609.27391},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.27391},
}
RIS
TY - UNPB
TI - Fractionation as a Tool to Control Mn/Al Site Mixing and Magnetism in CaMn_{2+x}Al_{10-x}
AU - Szymon Królak
AU - Sushma Kumari
AU - Sergey L. Bud'ko
AU - Paul C. Canfield
PY - 2026
DA - 2026/09/23
PB - arXiv
DO - 10.48550/arxiv.2609.27391
UR - https://arxiv.org/abs/2609.27391
AB - We report single crystal growth and physical property characterization of CaMn_{2+x}Al_{10-x} crystals grown using a fractionation approach. Three consecutive batches were obtained from the same initial melt composition, systematically sampling neighboring, narrow regions of the ternary Ca-Mn-Al phase diagram. Single-crystal X-ray diffraction measurements reveal Mn/Al site mixing, with the excess Mn concentration, x, decreasing systematically with decreasing decanting temperature. A low-temperature upturn in magnetization and a maximum in electrical resistivity both become progressively weaker with decreasing excess Mn content, suggesting that the previously reported magnetic properties attributed to stoichiometric CaMn_{2}Al_{10} instead arise from an inhomogeneous distribution of excess Mn atoms. More broadly, the results presented in this work demonstrate how fractionation can help distinguish intrinsic magnetic behavior from disorder-induced effects associated with an inhomogeneous distribution of magnetic ions in materials with a finite width of formation, particularly when itinerant magnetism is under consideration.
ER -