Magnetic Properties And High-pressure Characteristics Of Ag₂S：Eu³⁺ Diluted Magnetic Semiconductor Nanoparticles

Diluted magnetic semiconductor is also known as semi-magnetic semiconductors,often abbreviated as DMS in the literature. General transition metal ions or rare earthmetal ions disorderly alternative non-magnetic cation in the semiconductor compoundformed by a class of compounds of magnetic semiconductor materials called dilutedmagnetic semiconductors. Respect to the magnetic semiconductor, magnetic ion concentrationof diluted magnetic semiconductors is not high, so the weak magnetism, so called dilutemagnetic semiconductors.Dilute magnetic semiconductor materials both have thecharacteristics of the semiconductor material and the characteristics of the magneticmaterial, dilute magnetic semiconductor material is different from the ordinarysemiconductor materials in magnetic, optical and electrical properties. The continuousdevelopment of modern science and technology makes the method of preparation ofdiluted magnetic semiconductor nanomaterials are more and more, for example,Sol-Gel method, Inverted Micelle Coprecipitation method, Ion Implantation, ReactiveSputtering, CVD, and so on.In this article,our experimental group designed and built a new experimentaldevice:gas-liquid surface inorganic synthesis device. We choose Ag₂S as matrix inview of the narrow forbidden band,and the rare earth elements europium dopingThe samples were characterized by the XRD,EDS,TEM, XPS,UV and VSM.Based on the analysis of experimental data, we found that europium ions have beendoped into Ag₂S structure. The Ag₂S:Eu³⁺+nanoparticles have good optical propertiesand obvious ferromagnetic behavior. Application of first-principles explain the magnetic properties of the syntheticmaterial source, Based on the analysis,we prove that the ferromagnetic materialderived from the Eu doping. Theoretical calculations and experimental test results isconsistent.Finally, we reseach Ag₂S:Eu³⁺+diluted magnetic semiconductor nanoparticlesunder the high pressure X-ray synchrotron radiation. Based on the analysis ofexperimental data，we know that with the increase of pressure, samples fromcrystalline change into non-crystalline,non-crystalline phase transition pressure rangeis17.85GPa-20.18Gpa.Up to the maximum pressure28GPa has remainednon-crystalline samples.Sample after releasing the pressure has returned to themonoclinic crystal structure of α-Ag₂S. This result indicates that the sample isnon-crystalline phase transition is reversible, the sample was kept on the memory ofthe initial crystal structure.