Crystal structures and magnetic properties of Fe_1.93-xCo_xP_1-ySi_y compounds

In view of the interest that (Fe,Co)₂(P,Si) compounds have as potential permanent magnets, their structural and magnetic phase diagrams are explored focusing on establishing the range where the hexagonal Fe₂P-type structure is observed. In Fe_1.93-xCo_xP_1-ySi_y, the highest Si...

Enhanced reversibility of the magnetoelastic transition in (Mn,Fe)₂(P,Si) alloys via minimizing the transition-induced elastic strain energy

Magnetocaloric materials undergoing reversible phase transitions are highly desirable for magnetic refrigeration applications. (Mn,Fe)₂(P,Si) alloys exhibit a giant magnetocaloric effect accompanied by a magnetoelastic transition, while the noticeable irreversibility causes drastic degradation of the magnetocaloric properties...

Spiderweb Array: A Sparse Spin-Qubit Array

One of the main bottlenecks in the pursuit of a large-scale-chip-based quantum computer is the large number of control signals needed to operate qubit systems. As system sizes scale up, the number of terminals required to connect to off-chip control electronics quickly becomes unmanageable. Here, we discuss a quantum-dot spin-qubit...

(Fe,Co)₂(P,Si) rare-earth free permanent magnets: From macroscopic single crystals to submicron-sized particles

While rare-earth magnets exhibit unchallenged hard-magnetic properties, looking for alternatives based on inexpensive elements of non-critical supply remains of utmost interest. Here, we demonstrate that (Fe,Co)₂(P,Si) single crystals combine a large magnetocrystalline anisotropy (K₁ ≈ 0.9 MJ m⁻³ at 300 K),...

Switching the magnetostructural coupling in MnCoGe-based magnetocaloric materials

We performed neutron-diffraction experiments and density functional theory calculations to study the magnetostructural coupling in MnCoGeBx (x=0, 0.01, and 0.05) alloys. By varying the amount of boron addition, we are able to freely switch the magnetostructural coupling on and off in the MnCoGe alloys. It is found that the boron addition...

Reversible low-field magnetocaloric effect in Ni-Mn-In-based Heusler alloys

Ni-Mn-X (X = In, Sn, and Sb) based Heusler alloys show a strong potential for magnetic refrigeration owing to their large magnetocaloric effect (MCE) associated with first-order magnetostructural transition. However, the irreversibility of the MCE under low field change of 0–1 T directly hinders its application as an efficient magnetic coolant....