| Initial crystal system | unknown |
| Final crystal system | cubic |
| Initial space group | Unknown |
| Final space group | Pm3m |
| Direction | Both |
| Phase transition temperature | 227.0 (±5.0) K |
Hysteresis: NIL
| Initial crystal system | unknown |
| Phase transition temperature | K |
Starting materials: HBr, CH3NH2, Pb(NO3)2
Product: Partially deuterated MAPbBr3
Description: Add concentrated HBr to neutralize 20 g of 40% CH3NH2 aqueous solution. Add 7.1 g (0.021 mol) of Pb(NO3)2 solution drop-wise under vigorous stirring at 100°C to the concentrated CH3NH2Br solution. Red organic crystals form while dripping in the solution. Cool the solution to room temperature and filter out the crystals. Wash crystals firstly with n-butanol and then with benzene; subsequently dry crystals in vacuum. Partially N-deuterated samples required for the NMR studies were prepared using D-containing solutions. Refer to Page 413 Experimental.
Comment: Synthesis references: [1] Canadian Journal of Chemistry, 1987, 65(5): 1042-1046 https://doi.org/10.1139/v87-176 [2] D. WEBER. Z. Naturforsch. 33b, 1443 (1978).
Method: 2H and 14N NMR
Description: Measurements were carried out at 8.48 T with a Nicolet 360NB spectrometer using a broad band (16-58 MHz) variable-temperature 10 mm probe supplied by Nicolet. The 2-H and 14-N frequencies were 55.427 and 26.083 MHz, respectively. Refer to Page 414 Results section Existence of transitions subsection.
| Initial crystal system | unknown |
| Final crystal system | unknown |
| Initial space group | unknown |
| Final space group | unknown |
| Direction | both |
| Phase transition temperature | 148.35 (±0.05) K |
Hysteresis: NIL
| Initial crystal system | unknown |
| Final crystal system | unknown |
| Initial space group | unknown |
| Final space group | unknown |
| Direction | both |
| Phase transition temperature | 154.2 (±0.1) K |
Hysteresis: NIL
| Initial crystal system | unknown |
| Final crystal system | cubic |
| Initial space group | unknown |
| Final space group | cubic |
| Direction | both |
| Phase transition temperature | 235.1 (±0.2) K |
Hysteresis: NIL
Starting materials: HBr, CH3NH2, Pb(NO3)2
Product: MAPbBr3 Single-crystal
Description: Add concentrated HBr to neutralize 20 g of 40% CH3NH2 aqueous solution. Add 7.1 g (0.021 mol) of Pb(NO3)2 solution drop-wise under vigorous stirring at 100°C to the concentrated CH3NH3Br solution. Red organic crystals form while dripping in the solution. Cool the solution to room temperature and filter out the crystals. Wash crystals firstly with n-butanol and then with benzene; subsequently dry crystals in vacuum. Yield: 9.5 g.
Comment: Synthesis references: [1] Canadian Journal of Chemistry, 1987, 65(5): 1042-1046 https://doi.org/10.1139/v87-176 [2] D. WEBER. Z. Naturforsch. 33b, 1443 (1978).
Method: Adiabatic calorimetry
Description: The heat capacities were measured in an adiabatic calorimeter from 30 to 300 K, using sample masses of 12.8235 g MAPbBr3. Refer to Page 414 Table 1.
| Initial crystal system | unknown |
| Final crystal system | unknown |
| Initial space group | unknown |
| Final space group | unknown |
| Direction | both |
| Phase transition temperature | 150.0 K |
Hysteresis: NIL
| Initial crystal system | unknown |
| Final crystal system | unknown |
| Initial space group | unknown |
| Final space group | unknown |
| Direction | both |
| Phase transition temperature | 233.0 K |
Hysteresis: NIL
Starting materials: HBr, CH3NH2, Pb(NO3)2
Product: N-deuterated MAPbBr3 single crystals
Description: Add concentrated HBr to neutralize 20 g of 40% CH3NH2 aqueous solution (D2O-H2O mixture). Add 7.1 g (0.021 mol) of Pb(NO3)2 solution drop-wise under vigorous stirring at 100°C to the concentrated CH3NH3Br solution. Red organic crystals form while dripping in the solution. Cool the solution to room temperature and filter out the crystals. Wash crystals firstly with n-butanol and then with benzene; subsequently dry crystals in vacuum.
Comment: Synthesis references: [1] D. Weber, Z. Naturforsch. 33b, 1443 (1978).
Method: 2H and 14N NMR
Description: 2H and 14N NMR spectra were recorded at 55.4257 and 26.083 MHz, respectively, on a Nicolet 360 NB spectrometer (B0 = 8.48 T). Refer to Page 581.
| Initial crystal system | orthorhombic |
| Final crystal system | tetragonal |
| Initial space group | Pna2_1 |
| Final space group | P4mm |
| Direction | Unknown |
| Phase transition temperature | 148.8 K |
Hysteresis: NIL
| Initial crystal system | tetragonal |
| Final crystal system | tetragonal |
| Initial space group | P4mm |
| Final space group | I4/mcm |
| Direction | Unknown |
| Phase transition temperature | 154.0 K |
Hysteresis: NIL
| Initial crystal system | tetragonal |
| Final crystal system | cubic |
| Initial space group | I4/mcm |
| Final space group | Pm3m |
| Direction | Unknown |
| Phase transition temperature | 236.3 K |
Hysteresis: NIL
Starting materials: Pb(CH3CO2)2, MABr
Product: Orange MAPbBr3 cube-shaped crystals of 1-2 mm
Description: Add aqueous solution of Pb(CH3CO2)2 drop by drop to an excess quantity of hot aqueous MABr solution and cool slowly to 5 °C.
Method: Adiabatic calorimetry
Description: The heat capacities were measured with a computerized adiabatic calorimeter [1, 2]. The temperature ranges of the measurement were between 13 and 300 K. The mass of the calorimetric sample was 8.8810 g.
Comment: References: [1] Tatsumi M., Matsuo T., Suga H. and Seki S., Bull. chem. Soc. Jap. 48, 3060 (1975). [2] Matsuo T. and Suga H., Thermochim. Acta 88, 149 (1985).
| Initial crystal system | orthorhombic |
| Final crystal system | tetragonal |
| Initial space group | Pnma |
| Final space group | I4/mcm |
| Direction | Unknown |
| Phase transition temperature | 146.0 (±3.0) K |
Hysteresis: NIL
| Initial crystal system | tetragonal |
| Final crystal system | tetragonal |
| Initial space group | I4/mcm |
| Final space group | Unknown |
| Direction | Unknown |
| Phase transition temperature | 156.0 (±3.0) K |
Hysteresis: NIL
| Initial crystal system | tetragonal |
| Final crystal system | cubic |
| Initial space group | Unknown |
| Final space group | Pm3m |
| Direction | Unknown |
| Phase transition temperature | 232.0 (±3.0) K |
Hysteresis: NIL
Product: MAPbBr3 Powder
Description: Samples were prepared following well-described methods [1,2].
Comment: Synthesis references: [1] D. Weber, Z. Naturforsch. 33b (1978) 1443–1445. [2] O. Knop, R.E. Wasylishen, M.A. White, T.S. Cameron, M.J.M. Van Oort, Can. J. Chem. 68 (1990) 412–422.
Method: Powder X-ray diffraction
Description: X-ray diffraction measurements were performed from 120K to room temperature on samples mounted in 0.1mm diameter capillaries, mounted in an Enraf-Nonius Guinier-Simon camera, using CuKa_1 radiation. Refer to Page 98 Experimental.
| Initial crystal system | orthorhombic |
| Final crystal system | tetragonal |
| Initial space group | Pna2_1 |
| Final space group | P4/mmm |
| Direction | Unknown |
| Phase transition temperature | 144.5 K |
Hysteresis: NIL
| Initial crystal system | tetragonal |
| Final crystal system | tetragonal |
| Initial space group | P4/mmm |
| Final space group | I4/mcm |
| Direction | Unknown |
| Phase transition temperature | 155.1 K |
Hysteresis: NIL
| Initial crystal system | tetragonal |
| Final crystal system | cubic |
| Initial space group | I4/mcm |
| Final space group | Pm3m |
| Direction | Unknown |
| Phase transition temperature | 236.9 K |
Hysteresis: NIL
Starting materials: lead (II) acetate, CH3NH3+ (by adding a 40% solution of CH3NH2 in water), concentrated HBr
Product: Orange MAPbBr3 crystals
Description: CH3NH3PbBr3 was synthesized from lead (II) acetate and CH3NH3+ dissolved in concentrated HBr solution. The aqueous solution was cooled from l00°C to room temperature to obtain the orange crystals.
Method: Temperature-dependent Guinier-Simon photograph
Description: No method specified. Refer to Page 6374 Table I.