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We use muon spin relaxation (μSR) to investigate the magnetic properties of a bulk form diluted ferromagnetic semiconductor (DFS) Li 1.15 (Zn 0.9 Mn 0.1)P with T C ∼ 22 K. μSR results confirm the gradual development of ferromagnetic ordering below T C with a nearly 100% magnetic ordered volume. Despite its low carrier density, the relation between static internal field and Curie temperature observed for Li(Zn,Mn)P is consistent with the trend found in (Ga,Mn)As and other bulk DFSs, indicating these systems share a common mechanism for the ferromagnetic exchange interaction. Li 1+y (Zn 1−x Mn x)P has the advantage of decoupled carrier and spin doping, where Mn 2+ substitution for Zn 2+ introduces spins and Li + off-stoichiometry provides carriers. This advantage enables us to investigate the influence of overdoped Li on the ferromagnetic ordered state. Overdoping Li suppresses both T C and saturation moments for a certain amount of spins, which indicates that more carriers are detrimental to the ferromagnetic exchange interaction, and that a delicate balance between charge and spin densities is required to achieve highest T C .

La1−xSrx)(Zn1−yMny)AsO is a two-dimensional diluted ferromagnetic semiconductor that has the advantage of decoupled charge and spin doping. The substitution of Sr 2+ for La 3+ and Mn 2+ for Zn 2+ into the parent semiconductor LaZnAsO introduces hole carriers and spins, respectively. This advantage enables us to investigate the influence of carrier doping on the ferromagnetic ordered state through the control of Sr concentrations in (La1−xSrx)(Zn0.9Mn0.1)AsO. 10% Sr doping results in a ferromagnetic ordering below TC ∼ 30 K. Increasing Sr concentration up to 30% heavily suppresses the Curie temperature and saturation moments. Neutron scattering measurements indicate that no structural transition occurs for (La0.9Sr0.1)(Zn0.9Mn0.1)AsO below 300 K.

Using the density functional theory combined with dynamical mean-field theory, we have performed systematic study of the electronic structure and its band topology properties of Ce3Pt3Bi4 and Ce3Pd3Bi4. At high temperatures (∼290K), the electronic structures of both compounds resemble the open-core 4f density functional calculation results. For Ce3Pt3Bi4, clear hybridization gap can be observed below 72K, and its coherent momentum-resolved spectral function below 18K exhibits an topologically trivial indirect gap of ∼6 meV and resembles density functional band structure with itinerant 4f state. For Ce3Pd3Bi4, no clear hybridization gap can be observed down to 4K, and its momentum-resolved spectral function resembles electron-doped open-core 4f density functional calculations. The band nodal points of Ce3Pd3Bi4 at 4K are protected by the glidingmirror symmetry and form ring-like structure. Therefore, the Ce3Pt3Bi4 compound is topologically trivial Kondo insulator while the Ce3Pd3Bi4 compound is topological nodal-line semimetal.

We report the successful synthesis of a "122" diluted ferromagnetic semiconductor with n-type carriers, Ba(Zn,Co)2As2. Magnetization measurements show that the ferromagnetic transition occurs up to TC ∼ 45 K. Hall effect and Seebeck effect measurements jointly confirm that the dominant carriers are electrons. Through muon spin relaxation (µSR), a volume sensitive magnetic probe, we have also confirmed that the ferromagnetism in Ba(Zn,Co)2As2 is intrinsic and the internal field is static.