BiMnTeO6 : A multiaxis Ising antiferromagnet

Abstract

The crystal and magnetic properties of honeycomb BiMnTeO 6 have been studied between 1.5 K and 300 K using synchrotron X-rays and neutron scattering experiments. Commensurate magnetic ordering is observed below T N = 10 K, and corresponds to a non collinear spin arrangement, with spins tilted away from the anisotropy easy-axis set by the Jahn-Teller distortion of the MnO 6 octahedra. Inelastic scattering experiments show two main nearly localised magnetic excitations, which can be well described by an exchange Hamiltonian involving weak Mn-Mn magnetic interactions and a crystal field Hamiltonian characterizing the strong easy-axis anisotropy associated with the d z2 orbital ordering of Mn 3+ . The crystal field levels can be accurately calculated, taking into account a transverse molecular field imposed by the magnetic ordering of the neighbouring atoms below T N . This makes of BiMnTeO 6 an interesting example of a multi-axis Ising system in a self-imposed transverse magnetic field.

Minority Carrier Traps in Ion‐Implanted n‐Type Homoepitaxial GaN

“…As the collision cascades become less dilute due to the large ion mass, more of these intrinsic defects survive and bind to C N , explaining the ion mass dependence. In addition, the role of C interstitials (C i ) cannot be neglected: Matsubara and Bellotti [38] have shown that the C N C i complex has a similar energy position in the bandgap to that of C N alone.…”

“…[13] In addition, since A1 is detected irrespective of the implanted species, it is more likely that it has an intrinsic nature. Impurities might also play a role: According to theoretical studies performed by Matsubara and Bellotti, [38] the microscopic nature of this level can be linked to either positive charge state of C N or C N Si Ga . [39] Yet the former possibility can be ruled out because, if that were the case, both H1 and A1 would have the same concentrations, which is not the case.…”

“…Impurities might also play a role: According to theoretical studies performed by Matsubara and Bellotti, [38] the microscopic nature of this level can be linked to either positive charge state of C N or C N Si Ga . [39] Yet the former possibility can be ruled out because, if that were the case, both H1 and A1 would have the same concentrations, which is not the case. A peculiar feature of the A1 center is its different annealing behavior according to the implanted species.…”

“…As a matter of fact, the concentration of A2 might be compatible with the oxygen content of our samples (<10 15 cm À3 ). Other possible candidates might be the Si at a N site bound to a C at a Ga site (Si N C Ga ) [39] or C N bound to an oxygen at a Ga site (O Ga ). [39] A list of the detected levels is shown in Table 1.…”

Magnetism and ion diffusion in honeycomb layered oxide $${\hbox {K}_2\hbox {Ni}_2\hbox {TeO}_6}$$

“…Layered oxides have attracted considerable attention over the last decades owing to their intriguing physical and chemical properties across a wide scope of science, including, phase transitions (e.g. antiferromagnetism, superconductivity, Kitaev magnet) 2 – 5 , thermodynamics (e.g. fast ionic conductivity) 6 and unusual electromagnetic spin interactions (multiferroics, high-voltage electrochemistry) 7 – 9 .…”