中国物理B ›› 2016, Vol. 25 ›› Issue (1): 17601-017601.doi: 10.1088/1674-1056/25/1/017601

• SPECIAL TOPIC—Soft matter and biological physics (Review) • 上一篇    下一篇

Long-distance super-exchange and quantum magnetic relaxation in a hybrid metal-organic framework

Ying Tian(田英), Shipeng Shen(申世鹏), Junzhuang Cong(丛君状), Liqin Yan(闫丽琴), Yisheng Chai(柴一晟), Young Sun(孙阳)   

  1. Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
  • 收稿日期:2015-08-27 修回日期:2015-10-19 出版日期:2016-01-05 发布日期:2016-01-05
  • 通讯作者: Young Sun E-mail:youngsun@iphy.ac.cn
  • 基金资助:

    Project supported by the National Natural Science Foundation of China (Grant Nos. 11227405, 51371192, and 51371193) and the Chinese Academy of Sciences (Grant No. XDB07030200).

Long-distance super-exchange and quantum magnetic relaxation in a hybrid metal-organic framework

Ying Tian(田英), Shipeng Shen(申世鹏), Junzhuang Cong(丛君状), Liqin Yan(闫丽琴), Yisheng Chai(柴一晟), Young Sun(孙阳)   

  1. Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
  • Received:2015-08-27 Revised:2015-10-19 Online:2016-01-05 Published:2016-01-05
  • Contact: Young Sun E-mail:youngsun@iphy.ac.cn
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Grant Nos. 11227405, 51371192, and 51371193) and the Chinese Academy of Sciences (Grant No. XDB07030200).

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摘要：

The hybrid metal-organic framework [(CH3)2NH2]Fe(HCOO)3 with a perovskite-like structure exhibits a variety of unusual magnetic behaviors at low temperatures. While the long-distance super-exchange through the Fe-O-CH-O-Fe exchange path leads to a canted antiferromagnetic ordering at TN ～ 19 K, a second transition of magnetic blocking develops at TB ～ 9 K. The stair-shaped magnetization hysteresis loops below TB resemble the behaviors of resonant quantum tunneling of magnetization in single-molecular quantum magnets. Moreover, the magnetic relaxation also exhibits several features of resonant quantum relaxation, such as the exponential law with a single characteristic relaxation time, and the nonmonotonic dependence of relaxation rate on the applied magnetic field with a much faster relaxation around the resonant fields. The origin of quantum tunneling behaviors in the [(CH3)2NH2]Fe(HCOO)3 metal-organic framework is discussed in terms of magnetic phase separation due to the modification of hydrogen bonding on the long-distance super-exchange interaction.

关键词: metal-organic frameworks, resonant quantum relaxation, long-distance super-exchange interaction, hydrogen bonds

Abstract:

The hybrid metal-organic framework [(CH3)2NH2]Fe(HCOO)3 with a perovskite-like structure exhibits a variety of unusual magnetic behaviors at low temperatures. While the long-distance super-exchange through the Fe-O-CH-O-Fe exchange path leads to a canted antiferromagnetic ordering at TN ～ 19 K, a second transition of magnetic blocking develops at TB ～ 9 K. The stair-shaped magnetization hysteresis loops below TB resemble the behaviors of resonant quantum tunneling of magnetization in single-molecular quantum magnets. Moreover, the magnetic relaxation also exhibits several features of resonant quantum relaxation, such as the exponential law with a single characteristic relaxation time, and the nonmonotonic dependence of relaxation rate on the applied magnetic field with a much faster relaxation around the resonant fields. The origin of quantum tunneling behaviors in the [(CH3)2NH2]Fe(HCOO)3 metal-organic framework is discussed in terms of magnetic phase separation due to the modification of hydrogen bonding on the long-distance super-exchange interaction.

Key words: metal-organic frameworks, resonant quantum relaxation, long-distance super-exchange interaction, hydrogen bonds

中图分类号:  (General theory of resonances and relaxations)

  • 76.20.+q
75.30.Et (Exchange and superexchange interactions)