Tuning of the spin gap transition of spin dimer compound Ba₃Mn₂O₈by doping with La and V

Abstract

We have successfully synthesized the coupled spin dimer systems La(x)Ba(3-x)Mn(2)O(8) (x = 0, 0.2, 0.5, 1) and Ba(3)Mn(2-y)V(y)O(8) (y = 0.5, 1.0, 2.0). The magnetic properties have been investigated as a function of magnetic field and temperature down to 2 K. The susceptibility increases and the intradimer spin exchange interaction decreases with increase of La concentration. The most important finding in higher La doped systems reveals hysteresis in magnetization as a function of magnetic field. The substitution of La (x = 0.5, 1.0) for Ba induces ferromagnetism due to the formation of a mixed valence state of Mn and enhancement of the inter-bilayer ferromagnetic interaction. The replacement of Mn by non-magnetic V destroys the spin gap. La and V doping significantly affect the magnetic properties of the quantum antiferromagnetic compound Ba(3)Mn(2)O(8).

Persistence of magnons in a site-diluted dimerized frustrated antiferromagnet

“…Recently, there have been additional experimental results examining both magnetic and non-magnetic substitution of the Mn 5+ sites for Ba 3 Mn 2 O 8 . 43 The non-magnetic substituted In contrast to many other non-magnetically substituted gapped systems, no evidence for long range order was found in Ba 3 (Mn 1-x V x ) 2 O 8 . Rather, vanadium substitution creates additional quasi-elastic excitations.…”

Heat capacity of the site-diluted spin dimer system Ba3(Mn1−xVxSamulon1, Shapiro2, Fisher3 2011Phys. Rev. B113110View full textAdd to dashboardCite

“…1 Fig. 1(a)) 19 . For the relevant V concentrations studied here, the data do not suggest clustering of impurities, in which case, for the highest dilution studied, x = 0.046, the probability is 0.64 to find at least one neighboring V ion within 8Å of any given V impurity ( Fig.…”

Synthesis and crystal structure of a new hexagonal perovskite 7H-Ba7Li1.75Mn3.5O15.75with Mn4+/Mn5+charge distribution

“…In this respect it should be noted that Sr 4 LiMn 2 O 9 is deep-brown 27 and Ba 3 Mn 2 O 8 is green. 30 The size of the crystals is typical of the powder produced by solid-phase synthesis (1 µm or larger). According to the EDX data, the Ba/Mn ratio was found to be 2.12, i.e.…”