_{Temperature and magnetic field dependencies of the ESR spectra as well as the frequency-field (f-H) relations.}

Background

One-dimensional antiferromagnetic systems have attracted great attention due to exotic magnetic ground state. Spin clusters are another type of low-dimensional antiferromagnetic systems. When the clusters are coupled to form a cluster chain, new magnetic behaviors may appear.Recently, Li₂Cu₅Si₄O₁₄ was reported as a dimer-trimer chain compound. However, the susceptibility and specific heat data showed that the compound is ordered at T_N= 22 K.

What we discover?

In this work, we carried out high magnetic-field magnetization and ESR measurements for Li₂Cu₅Si₄O₁₄.Our frequency-dependent ESR spectra at 2 K reveal the development of two collinear antiferromagnetic sublattices with biaxial anisotropy, which is quite unusual because Li₂Cu₅Si₄O₁₄ contains five sublattices.

Why is this important?

According to our ESR results, Li₂Cu₅Si₄O₁₄ is three-dimensionally ordered and its magnetism might be described by pseudo-two-sublattice model composed of antiferromagnetically coupled dimer-trimer groups (­↑↑, ↑↓↑) and (↓↓, ↓↑↓). Our study provides new insight into the magnetism of cluster-based spin chains.

Why did we need WHMFC?

The high-field high-frequency ESR facility developed in the WHMFC was used to observe theantiferromagnetic resonances, which is not possible for low-field EPR.The high-field magnetization up to 55 T was measured to examine the possible magnetization plateaus in the dimer and trimer.

Who did the research?

X. P.Jin,¹Z. W. Ouyang,¹X.C.Liu,¹T. T. Xiao,¹J. J. Cao,¹Z. X.Wang,¹Z. C. Xia,¹and W. Tong²

¹Wuhan National High Magnetic Field Center & School of Physics, Huazhong University of Science and Technology, Wuhan430074, P. R. China.

²Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, P. R. China.

Acknowledgments

This work was supported by the National Natural Science Foundation of China (Grant Nos. 11874023 andU20A2073) and by the Fundamental Research Funds for the Central Universities (Grant No. 2019kfyXKJC008)

link：https://doi.org/10.1103/PhysRevB.104.174423