Magnetic resonance in cerium hexaboride caused by quadrupolar ordering

Abstract

Experimental evidence of the magnetic resonance in the antiferro-quadrupole phase of CeB6 is reported. We have shown that below orbital ordering temperature a new magnetic contribution from localized magnetic moments (LMM) emerge and gives rise to observed resonant phenomenon. This behaviour is hardly possible to expect in dense Kondo system, where LMM should vanish al low temperatures rather than emerge. From the other hand, in the quadrupole ordering concept, where magnetism of Ce magnetic ions is solely accounted, is difficult to explain splitting of magnetisation into components having different physical nature. Therefore an adequate theory explaining magnetic properties of CeB6 including magnetic resonance and orbital ordering appears on the agenda.Comment: 4 pages, Accepted paper for MISM05 proceeding

Magnetic Resonance and Nature of Magnetism in CeB₆

“…The latter fact reflects a specific feature of the pulsed field experiments in the superfluid helium, where the experimental set-up becomes more sensitive to a mechanical noise as compared to the case of normal helium (T =4.2 K). It is worth noting that the temperature measurements at ω/2π=60 GHz showed that the g-factor for magnetic resonance in the phase II is temperature independent [6,7]. This finding agrees with the result of the present experiment, which demonstrates a good coincidence of the g-factor values at 1.8 K and 4.2 K for the frequency ω/2π~100 GHz (fig.…”

Magnetic Resonance and Nature of Magnetism in CeB₆

“…The latter fact reflects a specific feature of the pulsed field experiments in the superfluid helium, where the experimental set-up becomes more sensitive to a mechanical noise as compared to the case of normal helium (T =4.2 K). It is worth noting that the temperature measurements at ω/2π=60 GHz showed that the g-factor for magnetic resonance in the phase II is temperature independent [6,7]. This finding agrees with the result of the present experiment, which demonstrates a good coincidence of the g-factor values at 1.8 K and 4.2 K for the frequency ω/2π~100 GHz (fig.…”

Magnetic spin resonance inCeB6

“…7. However the observed M 1 ͑T͒ dependence is completely different from the "naive" linear extrapolation of M͑T͒ in the phase I to the phase II, which was postulated in our previous study.…”

High-frequency study of the orbital ordering resonance in the strongly correlated heavy fermion metal CeB6

“…The latter fact reflects a specific feature of the pulse field experiments in the superfluid helium, where the experimental set-up becomes more sensitive to a mechanical noise as compared to the case of normal helium (T =4.2 K). It is worth noting that the temperature measurements at ω/2π=60 GHz showed that the g-factor for magnetic resonance in the AFQ phase is temperature independent [22][23][24]. This finding agrees with the result of the present experiment, which demonstrates a good coincidence of the g-factor values at 1.8 K and 4.2 K for the frequency ω/2π~100 GHz (fig.…”

“…It is visible that in the frequency range 44-99 GHz the single line A, which shifts almost linearly with magnetic field, is observed. The estimated g-factor value for the resonance A is about 1.6 in agreement with the previous findings [22][23][24]; in more detail the g-factors will be discussed below. Another characteristic aspect of the obtained data is the frequency independent kink in the vicinity of B ~1 T (fig.…”

“…2). However, similarly to the previous cavity experiments [22][23][24] in the pulsed field reflection measurements at T=4.2 K we have observed a kink at 1.6 T corresponding to the transition from the paramagnetic to the antiferro-quadrupole phase [1][2][3][4][5][6][7]. Thus, in our opinion, both resonances A and B reflect the high frequency properties of the orbitally ordered phase in CeB 6 .…”

Magnetic Resonance and Nature of Magnetism in CeB₆

“…The latter fact reflects a specific feature of the pulsed field experiments in the superfluid helium, where the experimental set-up becomes more sensitive to a mechanical noise as compared to the case of normal helium (T =4.2 K). It is worth noting that the temperature measurements at ω/2π=60 GHz showed that the g-factor for magnetic resonance in the phase II is temperature independent [6,7]. This finding agrees with the result of the present experiment, which demonstrates a good coincidence of the g-factor values at 1.8 K and 4.2 K for the frequency ω/2π~100 GHz (fig.…”

Magnetic spin resonance inCeB6

“…7. However the observed M 1 ͑T͒ dependence is completely different from the "naive" linear extrapolation of M͑T͒ in the phase I to the phase II, which was postulated in our previous study.…”

High-frequency study of the orbital ordering resonance in the strongly correlated heavy fermion metal CeB6

“…The latter fact reflects a specific feature of the pulse field experiments in the superfluid helium, where the experimental set-up becomes more sensitive to a mechanical noise as compared to the case of normal helium (T =4.2 K). It is worth noting that the temperature measurements at ω/2π=60 GHz showed that the g-factor for magnetic resonance in the AFQ phase is temperature independent [22][23][24]. This finding agrees with the result of the present experiment, which demonstrates a good coincidence of the g-factor values at 1.8 K and 4.2 K for the frequency ω/2π~100 GHz (fig.…”

“…It is visible that in the frequency range 44-99 GHz the single line A, which shifts almost linearly with magnetic field, is observed. The estimated g-factor value for the resonance A is about 1.6 in agreement with the previous findings [22][23][24]; in more detail the g-factors will be discussed below. Another characteristic aspect of the obtained data is the frequency independent kink in the vicinity of B ~1 T (fig.…”

“…2). However, similarly to the previous cavity experiments [22][23][24] in the pulsed field reflection measurements at T=4.2 K we have observed a kink at 1.6 T corresponding to the transition from the paramagnetic to the antiferro-quadrupole phase [1][2][3][4][5][6][7]. Thus, in our opinion, both resonances A and B reflect the high frequency properties of the orbitally ordered phase in CeB 6 .…”

Magnetic Resonance and Nature of Magnetism in CeB₆

“…The latter fact reflects a specific feature of the pulsed field experiments in the superfluid helium, where the experimental set-up becomes more sensitive to a mechanical noise as compared to the case of normal helium (T =4.2 K). It is worth noting that the temperature measurements at ω/2π=60 GHz showed that the g-factor for magnetic resonance in the phase II is temperature independent [6,7]. This finding agrees with the result of the present experiment, which demonstrates a good coincidence of the g-factor values at 1.8 K and 4.2 K for the frequency ω/2π~100 GHz (fig.…”

Magnetic spin resonance inCeB6

“…7. However the observed M 1 ͑T͒ dependence is completely different from the "naive" linear extrapolation of M͑T͒ in the phase I to the phase II, which was postulated in our previous study.…”

High-frequency study of the orbital ordering resonance in the strongly correlated heavy fermion metal CeB6

“…The latter fact reflects a specific feature of the pulse field experiments in the superfluid helium, where the experimental set-up becomes more sensitive to a mechanical noise as compared to the case of normal helium (T =4.2 K). It is worth noting that the temperature measurements at ω/2π=60 GHz showed that the g-factor for magnetic resonance in the AFQ phase is temperature independent [22][23][24]. This finding agrees with the result of the present experiment, which demonstrates a good coincidence of the g-factor values at 1.8 K and 4.2 K for the frequency ω/2π~100 GHz (fig.…”

“…It is visible that in the frequency range 44-99 GHz the single line A, which shifts almost linearly with magnetic field, is observed. The estimated g-factor value for the resonance A is about 1.6 in agreement with the previous findings [22][23][24]; in more detail the g-factors will be discussed below. Another characteristic aspect of the obtained data is the frequency independent kink in the vicinity of B ~1 T (fig.…”

“…2). However, similarly to the previous cavity experiments [22][23][24] in the pulsed field reflection measurements at T=4.2 K we have observed a kink at 1.6 T corresponding to the transition from the paramagnetic to the antiferro-quadrupole phase [1][2][3][4][5][6][7]. Thus, in our opinion, both resonances A and B reflect the high frequency properties of the orbitally ordered phase in CeB 6 .…”