In the concerned paper published in this journal,1 magnetic properties of a sample of Co2SnO4 annealed at 1200 °C were presented. This sample had some unreacted SnO2 as revealed by x-ray diffraction. Analysis of the magnetic data led to the conclusion that in Co2SnO4, ordering of the longitudinal spin component occurring at TN = 41 K is followed by spin-glass ordering of the transverse component at TSG = 39.1 K. In a follow-up paper by the authors,2 additional studies employing specific heat and ac susceptibilities on the 1200 °C annealed sample (S1200) along with a sample annealed at 1350 °C (S1350) confirmed the findings regarding TN and TSG. Importantly, the sample S1350 was found to be pure Co2SnO4 since no impurity lines in the x-ray diffraction pattern of this sample were detected, contrary to the case of S1200. For S1200, the temperature dependence of the dc magnetic susceptibility χ above TN in Ref. 1 was fitted to the Néel expression for ferrimagnets: 1/χ = (T/C) + (1/χ0) − σ/(T − θ) yielding the Curie constant C = 8.07 emu·K/mol·Oe. For the sample S1350, such an analysis has not yet presented either in Ref. 1 or Ref. 2.

The purpose of this addendum is twofold. First, it is noted that the above magnitude of C = 8.07 emu·K/mol·Oe for S1200 and subsequent derivation of the moment of Co2+ ion on the B-site of Co2SnO4, viz., μ(B) = 4.16 μB is not correct. This error resulted from the use of incorrect mass of the sample and the neglect of the presence of SnO2 impurity which were not considered in the calculations. This error is corrected here. Our second purpose is to present the first analysis of the χ vs. T data for the pure S1350 sample of Co2SnO4 above TN = 41 K, leading to somewhat different magnitudes of the moment of Co2+ on the B-site of Co2SnO4 and the exchange constants JAA, JBB, and JAB compared to those presented for S1200 in Ref. 1. The other results and conclusions presented in Refs. 1 and 2 are unaffected and are still valid.

The plots of the newly acquired data of dc magnetic susceptibility χ vs. T for the samples S1200 and S1350 are shown in Fig. 1, where the plots of 1/χ vs. T are shown in order to fit with the Neel's expression for ferrimagnets mentioned earlier. It is noted that for S1200, the mass of the sample used in calculating χ includes the mass of non-magnetic SnO2 impurity. It is evident that for all the temperatures, χ (S1200) < χ (S1350) and that the ratio χ (S1200)/χ (S1350) ≃ 0.75, nearly independent of temperature. This result of χ (S1200) < χ (S1350) can be understood in terms of the presence of non-magnetic SnO2 in S1200 which contributes to the mass of the sample but not to the measured χ. For this reason, the magnitude of the parameters C, χ0, σ, and θ of the Néel expression for only the sample S1350 are reliable. This fit is shown in Fig. 2 with C = 0.016266 emu·K/g·Oe = 4.889 emu·K/mol·Oe, 1/χ0 = 6.8936 × 103 g·Oe/emu, σ ≃ 3.0777 × 104 and θ = 39.5 K. Using the above magnitude of C which equals NAμ2/3kB yields μ = 6.25 μB as the magnetic moment per formula unit of Co2SnO4 where kB is the Boltzmann constant. Assuming the electronic states as [Co2+]A[Co2+Sn4+]BO4 on the A and B site with μ(Sn4+) = 0, and μ(Co2+)A = μ(A) = 3.87 μB discussed in Ref. 1, the moment on [Co2+]B = μ(B) is calculated using the relation μ2 = [μ(A)]2 + [μ(B)]2. This calculation yields μ(B) = 4.905 μB as the moment of Co2+ on the B-site, in agreement with the expected value for Co2+ with the partial contributions from spin-orbit interaction. In contrast, μ(A) = 3.87 μB represents spin only contribution with spin S = 3/2 and g = 2 since the tetrahedral coordination of the A-site does not allow orbital contribution. Note that the relation μ = μ(A) + μ(B) used in Ref. 1 is incorrect. The revised calculated exchange constants using the various parameters determined from the fit to the Néel expression for S1350 and the procedures described in Ref. 1 are JAA/kB = 4.05 K, JBB/kB = 4.28 K, and JAB/kB = 5.26 K.

FIG. 1.

Comparison of the temperature dependence of inverse susceptibility of the two samples of Co2SnO4: S1200 annealed at 1200 °C which has some unreacted SnO2 as a non-magnetic impurity; and S1350 annealed at 1350 °C which showed no impurity.1,2

FIG. 1.

Comparison of the temperature dependence of inverse susceptibility of the two samples of Co2SnO4: S1200 annealed at 1200 °C which has some unreacted SnO2 as a non-magnetic impurity; and S1350 annealed at 1350 °C which showed no impurity.1,2

Close modal
FIG. 2.

Temperature dependence of magnetic susceptibility χ and 1/ χ for S1350 sample of Co2SnO4. Circles are experimental points and solid lines are fits to the Neel's expression with the parameters of the fit given in the text.

FIG. 2.

Temperature dependence of magnetic susceptibility χ and 1/ χ for S1350 sample of Co2SnO4. Circles are experimental points and solid lines are fits to the Neel's expression with the parameters of the fit given in the text.

Close modal

In summary for pure Co2SnO4, the magnetic moment per formula unit is 6.25 μB with μ[Co2 + ]A = μ(A) = 3.87 μB, μ[Co2 + ]B = μ(B) = 4.905 μB, JAA/kB = 4.05 K, JBB/kB= 4.28 K, and JAB/kB = 5.26 K. The other results and conclusions presented in Refs. 1 and 2 are not affected by these changes.

1.
S.
Thota
and
M. S.
Seehra
,
J. Appl. Phys.
113
,
203905
(
2013
).
2.
S.
Thota
,
V.
Narang
,
S.
Nayak
,
S.
Sambasivam
,
B. C.
Choi
,
T.
Sarkar
,
M. S.
Andersson
,
R.
Mathieu
, and
M. S.
Seehra
,
J. Phys.: Condens. Matter
27
,
166001
(
2015
).