High-pressure magnetic properties of antiferromagnetic samarium up to 30 GPa using a SQUID-based vibrating coil magnetometer
High-pressure magnetic properties of antiferromagnetic samarium up to 30 GPa using a SQUID-based vibrating coil magnetometer
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DOI：
10.1103/physrevb.104.054431
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发表时间：
2021-08
影响因子：
3.7
通讯作者：
M. Mito;H. Kondo;Taiki Arase;Kunihiko Irie;S. Takagi;H. Deguchi;T. Tajiri;M. Ishizuka
中科院分区：
文献类型：
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作者：
M. Mito;H. Kondo;Taiki Arase;Kunihiko Irie;S. Takagi;H. Deguchi;T. Tajiri;M. Ishizuka
钐（Sm）在环境压力下，在${T}_{\ mathm {N}}(\text{hex})=106$ K的六角形位置具有反铁磁（AFM）有序，在${T}_{\ mathm {N}}(\text{cub})=14$ K的立方位置具有反铁磁（AFM）有序。从所谓的sm型结构到双六方紧密堆积（dhcp）结构的结构转变发生在大约6 GPa。根据电阻测量，随着压力的增加，${T}_{\ mathm {N}}$（hex）向低温侧移动的同时，${T}_{\ mathm {N}}$（cub）也向高温侧移动。我们使用基于squid的振动线圈磁力计在高达30 GPa的高压下对Sm进行直流磁测量，以追求高压下的${T}_{\ mathm {N}}$(cub)：磁测量显示在2 GPa以下的逐步异常。在dhcp结构中观察到铁磁（FM）异常，表明两个结构位点的自旋形成了FM磁化。在12 GPa以上的面心立方（fcc）结构中，磁信号发生了减弱。在20 GPa以上的扭曲fcc结构中，观察到FM力矩得到充分抑制，随后观察到提示超导可能性的抗磁信号。
Samarium (Sm) has antiferromagnetic (AFM) ordering at the hexagonal site at ${T}_{\mathrm{N}}(\text{hex})=106$ K, and at the cubic site at ${T}_{\mathrm{N}}(\text{cub})=14$ K at ambient pressure. The structural transition from the so-called Sm-type structure to the double hexagonal close-packed (dhcp) structure occurs at approximately 6 GPa. According to electrical resistance measurements, the shift of ${T}_{\mathrm{N}}$(hex) toward the low-temperature side occurs simultaneously with the shifting of ${T}_{\mathrm{N}}$(cub) toward the high-temperature side with increasing pressure. We conducted dc magnetic measurements on Sm at high pressure up to 30 GPa using a SQUID-based vibrating-coil-magnetometer to pursue ${T}_{\mathrm{N}}$(cub) at high pressure: The magnetic measurements revealed stepwise anomalies below 2 GPa. A ferromagnetic (FM) anomaly was observed in the dhcp structure, suggesting that spins at both structural sites formed the FM magnetization. In the face-centered cubic (fcc) structure at above 12 GPa, a reduction in the magnetic signal occurred. In the distorted fcc structure at above 20 GPa, sufficient suppression of the FM moment was observed and afterward the diamagnetic signal suggesting the possibility of superconductivity was observed.