Supporting Information (Online Material) for

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1 Supporting Information (Online Material) for Five-Fold Ordering in High-Pressure Perovskites RMn 3 O 6 (R = Gd-Tm and Y) Lei Zhang,, Yoshitaka Matsushita, Kazunari Yamaura,, Alexei A. Belik, *, Research Center for Functional Materials, National Institute for Materials Science (NIMS), 1 1 Namiki, Tsukuba, Ibaraki 35 44, Japan Graduate School of Chemical Sciences and Engineering, Hokkaido University, North 1 West 8, Kita-ku, Sapporo, Hokkaido 6-81, Japan Material Analysis Station, National Institute for Materials Science (NIMS), Sengen 1-2-1, Tsukuba, Ibaraki 35-47, Japan. * Alexei.Belik@nims.go.jp S 1

2 Table S1. Lattice Parameters (a, b, and c) Refined from Laboratory XRPD and Impurities in R 1 δ Mn 3 O 6 1.5δ and GdMn 3 y O 6 1.5y (Prepared at 6 GPa and 1673 K for 2 h). Composition a (Å) b (Å) c (Å) Impurity Weight LuMn YbMn Tm.88 Mn fraction of impurity * (Lu 1-x Mn x )MnO 3 82 % Mn 2 O 3 18 % (Yb 1-x Mn x )MnO 3 8 % Mn 2 O 3 2 % TmMn (Tm 1-x Mn x )MnO 3 28 % Er.88 Mn Ho.88 Mn Ho 1 δ Mn 7 O δ 2 % Ho.9 Mn Ho.95 Mn HoMn (Ho 1-x Mn x )MnO 3 4 % Y.88 Mn Y 1 δ Mn 7 O δ 2 % Y.9 Mn Y.95 Mn DyMn TbMn TbMn 2 O 5 13 % Tb 1 δ Mn 7 O δ 7 % GdMn GdMn 7 O 12 9 % GdMn GdMn GdMn GdMn (Gd 1-x Mn x )MnO 3 few percent ** EuMn EuMn 7 O % (Eu 1-x Mn x )MnO 3 3 % SmMn SmMn 7 O 12 5 % (Sm 1-x Mn x )MnO 3 38 % * The weight fraction was estimated from the refined scale factors during the Rietveld fitting. ** Because of its small amount, it was difficult to find/catch the lattice parameters of (Gd 1-x Mn x )MnO 3 impurity during the Rietveld fitting; therefore, the weight fraction of this impurity could not be estimated from the Rietveld fitting. S 2

3 (Tm 1-x Mn x )MnO 3 : x 1/3 space group: Pnma a = (2) Å b = (4) Å c = (2) Å TmMn 3 O 6 6 GPa, 14 C, 2 h, in Pt Intensity 2 1 (Tm,Mn)MnO wt. % θ / Tm.88 Mn 3 O GPa, 14 C, 2 h, in Pt 25 Intensity θ / Figure S1a. Fragments of experimental laboratory X-ray powder diffraction patterns measured at room temperature (brown crosses) with fitting results for samples with the total compositions of TmMn 3 O 6 and Tm.88 Mn 3 O S 3

4 6 HoMn 3 O Intensity (Ho,Mn)MnO wt. % θ / 5 Ho.95 Mn 3 O Intensity θ / Figure S1b. Fragments of experimental laboratory X-ray powder diffraction patterns measured at room temperature (brown crosses) with fitting results for samples with the total compositions of HoMn 3 O 6 and Ho.95 Mn 3 O S 4

5 6 Ho.9 Mn 3 O Intensity θ / 6 Ho.88 Mn 3 O Intensity Ho 1-xMn 7O x 2. wt. % θ / Figure S1c. Fragments of experimental laboratory X-ray powder diffraction patterns measured at room temperature (brown crosses) with fitting results for samples with the total compositions of Ho.9 Mn 3 O 5.85 and Ho.88 Mn 3 O S 5

6 GdMn 3 O 6 6 GPa, 14 C, 2 h, in Pt Intensity Intensity θ / GdMn 7O wt. % θ / 1 8 GdMn 2.75 O GPa, 14 C, 2 h, in Pt Intensity Intensity θ / θ / Figure S1d. Fragments of experimental laboratory X-ray powder diffraction patterns measured at room temperature (brown crosses) with fitting results for samples with the total compositions of GdMn 3 O 6 and GdMn 2.75 O Arrows show reflections from (Gd 1- xmn x )MnO 3. S 6

7 1 DyMn 3 O 6 6 GPa, 14 C, 2 h, in Pt 8 6 Intensity θ / DyMn 3 O 6 After TG-DTA in air up to 9 C 2 Intensity DyMn 2O 5 2 wt. % θ / Figure S1e. Fragments of experimental laboratory X-ray powder diffraction patterns measured at room temperature (brown crosses) with fitting results for samples with the total compositions of DyMn 3 O 6. (Up) As-synthesized, (down) after a TG-DTA experiment performed up to 1173 K (heating-cooling rate was 1 K/min) in air on a Mettler Toledo instrument. S 7

8 Figure S2. Crystal Structure of DyMn 3 O 6 with Thermal Ellipsoids. S 8

9 K.8 Cp / T (J K 2 mol 1 ) T N2 = 2 K T N1 = 75 K Tm.88 Mn 3 O 5.82 Tm88, Oe, cooling Tm.88, Oe, heating Tm88, 9 koe, cooling Tm.88, 9 koe, heating Tm88, Oe, cooling Tm.88, Oe, heating Tm88, 9 koe, cooling Tm.88, 9 koe, heating Figure S3. (Up) Specific heat of Tm.88 Mn 3 O 5.82 (plotted as C p /T vs T) measured at H = Oe and 9 koe on cooling and heating. The anomaly at T N2 was very sharp and with hysteresis; these facts could indicate that there is also a change in the crystal structure. (Down) Lowtemperature details below 4 K. S 9

10 χ (cm 3 / mol) Hz 7 Hz 11 Hz 3 Hz 5 Hz Ho.95 Mn 3 O (a) H ac =.5 Oe H dc = Oe 1. χ (cm 3 / mol) Y.95 Mn 3 O Hz 7 Hz 11 Hz 3 Hz 5 Hz (b) Ho.95 Mn 3 O Y.95 Mn 3 O Figure S4a. (a) Real parts of the ac susceptibility (χ vs T) of Ho.95 Mn 3 O and Y.95 Mn 3 O (the curves for Ho.95 Mn 3 O are shifted by +.5 for the clarity). (b) Imaginary parts of the ac susceptibility (χ vs T) of Ho.95 Mn 3 O and Y.95 Mn 3 O (the curves for Ho.95 Mn 3 O are shifted by +.12 for the clarity). These figures illustrate that magnetic properties of Ho.95 Mn 3 O and Y.95 Mn 3 O are very close to each other, and their properties are determined by the stoichiometry and the size of R 3+ cations (Ho 3+ (r VIII = 1.15 Å) is very close to Y 3+ (r VIII = 1.19 Å)). S 1

11 χ (cm 3 / mol) Hz 7 Hz 11 Hz 3 Hz 5 Hz Ho.9 Mn 3 O 5.85 (a) H ac =.5 Oe H dc = Oe Y.9 Mn 3 O Hz 7 Hz 11 Hz 3 Hz 5 Hz (b) χ (cm 3 / mol).2.1 Ho.9 Mn 3 O Y.9 Mn 3 O Figure S4b. (a) Real parts of the ac susceptibility (χ vs T) of Ho.9 Mn 3 O 5.85 and Y.9 Mn 3 O 5.85 (the curves for Ho.9 Mn 3 O 5.85 are shifted by +2 for the clarity). (b) Imaginary parts of the ac susceptibility (χ vs T) of Ho.9 Mn 3 O 5.85 and Y.9 Mn 3 O 5.85 (the curves for Ho.9 Mn 3 O 5.85 are shifted by +.18 for the clarity). These figures illustrate that magnetic properties of Ho.9 Mn 3 O 5.85 and Y.9 Mn 3 O 5.85 are very close to each other, and their properties are determined by the stoichiometry and the size of R 3+ cations (Ho 3+ (r VIII = 1.15 Å) is very close to Y 3+ (r VIII = 1.19 Å)). S 11

12 χ (cm 3 / mol) ZFC, 1 Oe, HoMn3O6 FCC, 1 Oe, HoMn3O6 ZFC, 1 Oe, Ho.95Mn3O5.925 FCC, 1 Oe, Ho.95Mn3O5.925 ZFC, 1 Oe, Ho.9Mn3O5.85 FCC, 1 Oe, Ho.9Mn3O5.85 ZFC, 1 Oe, Ho.88Mn3O5.82 FCC, 1 Oe, Ho.88Mn3O Impurity of Ho.9 Mn 7 O T N 19 K dχt/dt (cm 3 / mol) q-zfc, 1 Oe, Ho FCC, 1 Oe, Ho ZFC, 1 Oe, Ho.95 FCC, 1 Oe, Ho.95 ZFC, 1 Oe, Ho.9 FCC, 1 Oe, Ho.9 ZFC, 1 Oe, Ho.88 FCC, 1 Oe, Ho Impurity of (Ho 1-x Mn x )MnO 3 T N 1 K Figure S5a. ZFC and FCC dc χ vs T and dχt/dt vs T curves of HoMn 3 O 6, Ho.95 Mn 3 O 5.925, Ho.9 Mn 3 O 5.85, and Ho.88 Mn 3 O 5.82 at 1 Oe. S 12

13 q-zfc, 1 Oe, HoMn3O6 FCC, 1 Oe, HoMn3O6 q-zfc, 1 koe, HoMn3O6 FCC, 1 koe, HoMn3O6 χ (cm 3 / mol) 1..5 Impurity of (Ho 1-x Mn x )MnO 3 T N 1 K q-zfc, 1 Oe, Ho.95 1 FCC, 1 Oe, Ho.95 q-zfc, 1 koe, Ho.95 8 FCC, 1 koe, Ho χ (cm 3 / mol) 6 4 y =.4561x R 2 = µ eff = (14)µ B θ = 31.(8) K 1 χ 1 (mol / cm 3 ) Figure S5b. ZFC and FCC dc χ vs T and χ 1 vs T curves of HoMn 3 O 6 and Ho.95 Mn 3 O at 1 Oe and 1 koe. Note that negative magnetization was observed on the 1 Oe FCC curve of HoMn 3 O 6 ; the origin seems to be the two-phase nature of the sample (see, for example, Belik, A. A. Negative Exchange Bias in Polycrystalline Hexagonal ScMnO 3, InMnO 3, YMnO 3, 4H-SrMnO 3, and 6H-SrMnO 3 and Perovskite YMnO 3 : Effects of Impurities. J. Phys. Soc. Jpn. 214, 83, 7473; Belik, A. A. Fresh Look at the Mystery of Magnetization Reversal in YVO 3. Inorg. Chem. 213, 52, ). S 13

14 18 q-zfc, 1 Oe, Ho FCC, 1 Oe, Ho.9 q-zfc, 1 koe, Ho.9 FCC, 1 koe, Ho.9 15 χ (cm 3 / mol) y =.4795x R 2 = µ eff = (9)µ B θ = 24.7(5) K 1 χ 1 (mol / cm 3 ) Cp / T (J K 2 mol 1 ) Ho88, Oe, cooling Ho88, Oe, heating Ho88, 7 koe, cooling Figure S5c. (Up) ZFC and FCC dc χ vs T and χ 1 vs T curves of Ho.9 Mn 3 O 5.85 at 1 Oe and 1 koe. (Down) Specific heat of Ho.88 Mn 3 O 5.82 (plotted as C p /T vs T) measured at H = Oe on cooling and heating and at H = 7 koe on cooling. Note that a kink/hole between about 18 and 25 K (marked by an oval) is most probably an instrumental artifact (because we observed the same kink/hole on many other samples measured on the same specific heat puck during that period). S 14

15 1. DyMn 3 O 6 Sample No. 4 Cp / T (J K 2 mol 1 ) DyMn3O6-4, Oe, cooling DyMn3O6-4, 9 koe, cooling Figure S6. Specific heat of DyMn 3 O 6 (plotted as C p /T vs T) measured at H = Oe and 9 koe on cooling. S 15

16 χ (cm 3 / mol) ZFC, 1 Oe, GdMn2.833O5.75 FCC, 1 Oe, GdMn2.833O5.75 ZFC, 1 koe, GdMn2.833O5.75 FCC, 1 koe, GdMn2.833O5.75 GdMn O Impurity of GdMn 7 O GdMn O 5.75 Cp / T (J K 2 mol 1 ) Impurity of GdMn 7 O 12 T N 87 K GdMn3O6, Oe, cooling GdMn3O6, Oe, heating GdMn2.833O5.75, Oe, cooling GdMn2.833O5.75, 9 koe, cooling Figure S7a. (Up) ZFC and FCC dc χ vs T curves of GdMn O 5.75 at 1 Oe and 1 koe. Even though the GdMn O 5.75 sample was single phase based on laboratory XRPD, magnetic measurements showed the presence of a trace amount of GdMn 7 O 12 impurity. (Down) Specific heat of GdMn 3 O 6 and GdMn O 5.75 (plotted as C p /T vs T) measured at H = Oe on cooling and heating and at H = 9 koe on cooling. GdMn 3 O 6 contained about 9 wt. % of GdMn 7 O 12 impurity; this impurity with this amount could be clearly seen on specific heat. S 16

17 25 ZFC, 1 Oe, GdMn2.833O5.75 FCC, 1 Oe, GdMn2.833O5.75 χ 1 (mol / cm 3 ) GdMn O Impurity of GdMn 7 O ZFC, 1 koe, GdMn2.833O5.75 FCC, 1 koe, GdMn2.833O GdMn O χ 1 (mol / cm 3 ) 15 1 y =.6499x R 2 = µ eff = 11.95(4)µ B /f.u. θ = 2.6(2) K dχt/dt (cm 3 / mol) Figure S7b. ZFC and FCC dc χ 1 vs T curves of GdMn O 5.75 at 1 Oe and 1 koe. The dχt/dt vs T curves of GdMn O 5.75 at 1 koe are also shown on the bottom figure (black triangles; the right-hand axis). S 17

18 χ (cm 3 / mol) GdMn O 5.75 H ac = f =.5 Oe, 3 Hz.5 Oe, 3 Hz 5 Oe, 3 Hz H dc = Oe Oe, 3 Hz.5 Oe, 3 Hz 5 Oe, 3 Hz χ (cm 3 / mol) Figure S7c. Real χ (up) and imaginary χ (down) parts of the ac susceptibility as a function of temperature (2 1 K) for GdMn O Measurements were performed on cooling at a zero static magnetic field using the ac fields with the amplitudes H ac =.5,.5, and 5 Oe and the frequency f = 3 Hz. Additional anomalies are seen near 3 K on the χ vs T curves. S 18

19 χ (cm 3 / mol) GdMn O 5.75 H dc = Oe H ac =.5 Oe f = 2 Hz 7 Hz 11 Hz 3 Hz 5 Hz.3 χ (cm 3 / mol) Hz 7 Hz 11 Hz 3 Hz 5 Hz Figure S7d. Real χ (up) and imaginary χ (down) parts of the ac susceptibility as a function of temperature (2 1 K) for GdMn O Measurements were performed on cooling at a zero static magnetic field using the ac field with the amplitude H ac =.5 Oe and frequencies f = 2, 7, 11, 3, and 5 Hz. S 19

20 χ (cm 3 / mol) (a) 9..5 Oe, 3 Hz 8..5 Oe, 3 Hz 5 Oe, 3 Hz Tm.88 Mn 3 O 5.82 H dc = Oe (b).5 Oe, 3 Hz.5 Oe, 3 Hz.5 Oe, 3 Hz.5 Oe, 3 Hz 5 Oe, 3 Hz 1..8 χ (cm 3 / mol) Tm.88 Mn 3 O Figure S8a. (a) Real χ and (b) imaginary χ parts of the ac susceptibility as a function of temperature (2 1 K) for Tm.88 Mn 3 O Measurements were performed on cooling at a zero static magnetic field (H dc = Oe) using the ac fields with the amplitudes H ac =.5,.5, and 5 Oe and one frequency f = 3 Hz. S 2

21 6. 5. (a).5 Oe, 3 Hz.5 Oe, 3 Hz 5 Oe, 3 Hz H dc = Oe χ (cm 3 / mol) Er.88 Mn 3 O (b).5 Oe, 3 Hz.5 Oe, 3 Hz 5 Oe, 3 Hz χ (cm 3 / mol) Er.88 Mn 3 O Figure S8b. (a) Real χ and (b) imaginary χ parts of the ac susceptibility as a function of temperature (2 11 K) for Er.88 Mn 3 O Measurements were performed on cooling at a zero static magnetic field (H dc = Oe) using the ac fields with the amplitudes H ac =.5,.5, and 5 Oe and one frequency f = 3 Hz. S 21

22 χ (cm 3 / mol) (a) Ho.9 Mn 3 O Oe, 3 Hz.5 Oe, 3 Hz 5 Oe, 3 Hz H dc = Oe (b).5 Oe, 3 Hz.5 Oe, 3 Hz 5 Oe, 3 Hz χ (cm 3 / mol).4.2. Ho.9 Mn 3 O Figure S8c. (a) Real χ and (b) imaginary χ parts of the ac susceptibility as a function of temperature (2 11 K) for Ho.9 Mn 3 O Measurements were performed on cooling at a zero static magnetic field (H dc = Oe) using the ac fields with the amplitudes H ac =.5,.5, and 5 Oe and one frequency f = 3 Hz. S 22

23 χ (cm 3 / mol) (a) Ho.95 Mn 3 O Oe, 3 Hz.5 Oe, 3 Hz 5 Oe, 3 Hz H dc = Oe..3 (b).5 Oe, 3 Hz.5 Oe, 3 Hz 5 Oe, 3 Hz χ (cm 3 / mol).2.1. Ho.95 Mn 3 O Figure S8d. (a) Real χ and (b) imaginary χ parts of the ac susceptibility as a function of temperature (2 11 K) for Ho.95 Mn 3 O Measurements were performed on cooling at a zero static magnetic field (H dc = Oe) using the ac fields with the amplitudes H ac =.5,.5, and 5 Oe and one frequency f = 3 Hz. S 23

24 χ (cm 3 / mol) (a) Y.9 Mn 3 O Oe, 3 Hz.5 Oe, 3 Hz 5 Oe, 3 Hz H dc = Oe (b).5 Oe, 3 Hz.5 Oe, 3 Hz 5 Oe, 3 Hz χ (cm 3 / mol) Y.9 Mn 3 O Figure S8e. (a) Real χ and (b) imaginary χ parts of the ac susceptibility as a function of temperature (2 11 K) for Y.9 Mn 3 O Measurements were performed on cooling at a zero static magnetic field (H dc = Oe) using the ac fields with the amplitudes H ac =.5,.5, and 5 Oe and one frequency f = 3 Hz. S 24

25 χ (cm 3 / mol) (a) 3..5 Oe, 3 Hz.5 Oe, 3 Hz 5 Oe, 3 Hz Y.95 Mn 3 O H dc = Oe..4.3 (b).5 Oe, 3 Hz.5 Oe, 3 Hz 5 Oe, 3 Hz χ (cm 3 / mol).2.1. Y.95 Mn 3 O Figure S8f. (a) Real χ and (b) imaginary χ parts of the ac susceptibility as a function of temperature (2 1 K) for Y.95 Mn 3 O Measurements were performed on cooling at a zero static magnetic field (H dc = Oe) using the ac fields with the amplitudes H ac =.5,.5, and 5 Oe and one frequency f = 3 Hz. S 25

26 χ (cm 3 / mol) (a) Oe, 3 Hz.5 Oe, 3 Hz Oe, 3 Hz H dc = Oe DyMn 3 O (b).5 Oe, 3 Hz.5 Oe, 3 Hz 5 Oe, 3 Hz χ (cm 3 / mol).15.5 DyMn 3 O Figure S8g. (a) Real χ and (b) imaginary χ parts of the ac susceptibility as a function of temperature (2 1 K) for DyMn 3 O 6. Measurements were performed on cooling at a zero static magnetic field (H dc = Oe) using the ac fields with the amplitudes H ac =.5,.5, and 5 Oe and one frequency f = 3 Hz. S 26

27 χ 1 (mol / cm 3 ) ZFC, 1 koe, Y.95 FCC, 1 koe, Y.95 ZFC, 1 koe, Y.9 FCC, 1 koe, Y.9 µ eff = 8.66(17)µ B θ = 78(2) K µ eff = 8.27(11)µ B θ = 7.8(1.1) K χ (cm 3 / mol) ZFC, 1 Oe, Y.88 FCC, 1 Oe, Y.88 ZFC, 1 Oe, Y.9 FCC, 1 Oe, Y.9 ZFC, 1 koe, Y.95 FCC, 1 koe, Y.95 5 Impurity of Y.9 Mn 7 O T N 18 K Figure S9. (Up) ZFC and FCC dc χ 1 vs T curves of Y.95 Mn 3 O and Y.9 Mn 3 O 5.85 at 1 koe with the Curie-Weiss fits. (Down) ZFC and FCC dc χ vs T curves of Y.95 Mn 3 O 5.925, Y.9 Mn 3 O 5.85, and Y.88 Mn 3 O 5.82 at 1 Oe. This figure illustrates strong compositional dependence of magnetic properties for Y.95 Mn 3 O and Y.9 Mn 3 O Properties of Y.9 Mn 3 O 5.85 and Y.88 Mn 3 O 5.82 were very close to each other, except for the presence of Y.9 Mn 7 O impurity in Y.88 Mn 3 O S 27

28 Magnetization (µb / f.u.) Er.88Mn3O5.82, 5 K Tm.88Mn3O5.82, 5 K Tm.88Mn3O5.82, 3 K Magnetic Field (koe) 3 2 Er.88Mn3O5.82, 5 K Tm.88Mn3O5.82, 5 K Tm.88Mn3O5.82, 3 K Magnetization (µb / f.u.) Magnetic Field (koe) Figure S1a. M-H curves of Tm.88 Mn 3 O 5.82 at 5 K and 3 K and Er.88 Mn 3 O 5.82 at 5 K. Full curves are given on the top figure, and details are given on the bottom figure. S 28

29 8. 6. Ho.95Mn3O5.925, 5 K DyMn3O6-1, 5 K Magnetization (µb / f.u.) Magnetic Field (koe) Ho.95Mn3O5.925, 5 K DyMn3O6-1, 5 K Magnetization (µb / f.u.) Magnetic Field (koe) Figure S1b. M-H curves of DyMn 3 O 6 at 5 K in comparison with those of Ho.95 Mn 3 O at 5 K. Full curves are given on the top figure, and details are given on the bottom figure. S 29

30 Magnetization (µb / f.u.) GdMn2.833O5.75, 5 K GdMn3O6, 5 K GdMn2.75O5.625, 5 K Magnetic Field (koe) Magnetization (µb / f.u.) GdMn2.833O5.75, 5 K GdMn3O6, 5 K GdMn2.75O5.625, 5 K Magnetic Field (koe) Figure S1c. M-H curves of GdMn 3 O 6, GdMn O 5.75, and GdMn 2.75 O at 5 K. Full curves are given on the top figure, and details are given on the bottom figure. S 3

31 9 8 T, cooling T, heating 9 T, cooling 9 T, heating Tm.88 Mn 3 O 5.82 f = 665 khz Dielectric constant, ε Dielectric constant, ε T, cooling T, heating 9 T, cooling 9 T, heating DyMn 3 O 6 f = 665 khz Figure S11a. Temperature dependence of dielectric constant of Tm.88 Mn 3 O 5.82 and DyMn 3 O 6 on cooling and heating at and 9 koe at a frequency of 665 khz. There are no dielectric anomalies at magnetic transition temperatures, and the magnetodielectric effect is negligible. S 31

32 15 DyMn 3 O 6 Dielectric constant, ε Hz 31 Hz 93 Hz 2.71 khz 8.16 khz 24.5 khz 73.7 khz 221 khz 665 khz 2 MHz Dielectric Loss Hz 31 Hz 93 Hz 2.71 khz 8.16 khz 24.5 khz 73.7 khz 221 khz 665 khz 2 MHz Figure S11b. Temperature dependence of dielectric constant and loss tangent of DyMn 3 O 6 at different frequencies measured on cooling at a zero magnetic field. S 32

33 14 Tm.88 Mn 3 O 5.82 Dielectric constant, ε Hz 31 Hz 93 Hz 2.71 khz 8.16 khz 24.5 khz 73.7 khz 221 khz 665 khz 2 MHz.25 4 Dielectric Loss Hz 31 Hz 93 Hz 2.71 khz 8.16 khz 24.5 khz 73.7 khz 221 khz 665 khz 2 MHz Figure S11c. Temperature dependence of dielectric constant and loss tangent of Tm.88 Mn 3 O 5.82 at different frequencies measured on cooling at a zero magnetic field. S 33