We report experimental studies of a series of BaFe2S3−xSex (0≤x≤3) single crystals and powder specimens using x-ray diffraction, neutron diffraction, muon spin relaxation, and electrical transport measurements. A structural transformation from Cmcm (BaFe2S3) to Pnma (BaFe2Se3) was identified around x=0.7∼1. Neutron diffraction measurements on the samples with x = 0.2, 0.4, and 0.7 reveal that the Neˊel temperature of the stripe antiferromagnetic order is gradually suppressed from ∼120 to 85 K, while the magnitude of the ordered Fe2+ moments shows very little variation. Similarly, the block antiferromagnetic order in BaFe2Se3 remains robust for 1.5≤x≤3 with negligible variation in the ordered moment and a slight decrease of the Neˊel temperature from 250 K (x=3) to 225 K (x=1.5). The sample with x=1 near the Cmcm and Pnma border shows coexisting, two-dimensional, short-range stripe- and block-type antiferromagnetic correlations. The system remains insulating for all x, but the thermal activation gap shows an abrupt increase when traversing the boundary from the Cmcm stripe phase to the Pnma block phase. The results demonstrate that the crystal structure, magnetic order, and electronic properties are strongly coupled in the BaFe2S3−xSex system.
@article{arxiv.2004.06426,
title = {Structural, magnetic, and electronic evolution of the spin-ladder system BaFe$_2$S$_{3-x}$Se$_x$ with isoelectronic substitution},
author = {Jia Yu and Meng Wang and Benjamin A. Frandsen and Hualei Sun and Junjie Yin and Zengjia Liu and Shan Wu and Ming Yi and Zhijun Xu and Arani Acharya and Qingzhen Huang and Edith Bourret-Courchesne and Jeffrey W. Lynn and Robert J. Birgeneau},
journal= {arXiv preprint arXiv:2004.06426},
year = {2020}
}