Fullerene (C60) systems

(1) Materials

Alkali metal doped systems AxC60

x=1
Compounds	structure	lattice parameters	properties	ref.	
K1C60	fcc	a=14.07 Å (473K)	monomeric phase (T>400K)	1	
	orthorhombic	a=9.109 Å, b=9.953 Å, 
c=14.321 Å	1D-polymer, metal	2	
	monoclinic	a=17.153 Å, b=9.793 Å, 
c=19.224 Å, b=124.1˚	dimeric phase	3, 4	
Rb1C60	fcc	a=14.08 Å (473K)	monomeric phase(T>400K)	1,5	
	orthorhombic	a=9.138 Å, b=10.107 Å, 
c=14.233 Å	1D-polymer, SDW(Tn=50K)	2	
	monoclinic	a=17.141 Å, b=9.929 Å, 
c=19.227 Å, b=124.4˚	dimeric phase	3, 4	
Cs1C60	fcc	a=14.115 Å (473K)	monomeric phase (T>400K)	6	
	fcc		monomeric phase (T<100K),metal	6	
	orthorhombic	a=9.095 Å, b=10.225 Å, 
c=14.173 Å	1D-polymer, SDW(Tn=50K)	6	
	monoclinic		dimeric phase	6	
Na(THF)5C60				7	
Nax(THF)yC60	hexagonal	a=15.331 Å, c=9.965 Å	metal (x~0.4, y~2.2)	8	

x=2
Compounds	structure	lattice parameters	properties	ref.	
NaxC60	fcc -> sc	a=14.189 Å	 1<x<3	9	
Na2C60	fcc -> sc	a=14.19(1) Å	MI transition at 50K		
(NH3)8Na2C60	rhombohedral	a=12.221 Å, c=22.296 Å		10	

x=3
Compounds	structure	lattice parameters	properties	ref.	
Li2RbC60	fcc	a=13.896 Å 		11, 12	
Li2CsC60	fcc	a=14.075 Å		11, 12	
Li3CsC60	fcc	a=14.080 Å	sc Tc=10.5K	13	
Na3C60	fcc	a=14.191 Å		14	
Na2KC60	fcc -> s.c.	a=14.122 Å	sc Tc=2.5K	11, 12	
Na2RbC60	fcc -> s.c.	a=14.092 Å	sc Tc=3.5K	11, 12	
	monoclinic	a=13.711 Å, b=14.554 Å, 
c=9.373 Å, b=133.53˚ 	1D-polymer	15, 16	
Na2Rb0.3Cs0.7C60	monoclinic		1D-polymer, antiferromagnet
TN=15K		
Na2CsC60	fcc -> s.c.	a=14.126 Å	sc Tc=12K	11, 12	
K3C60	fcc 	a=14.240 Å	sc Tc=19K	17, 18	
KxRb3-xC60	fcc		sc, 0<x<3	19	
K2CsC60	fcc	a=14.292 Å	sc Tc=24K	19	
Rb3C60	fcc	a=14.384 Å	sc Tc=29K	20	
Rb2CsC60	fcc	a=14.431 Å	sc Tc=31K	19	
RbCs2C60	fcc	a=14.555 Å	sc Tc=33K	20	
Cs3C60	bco	a=14.126 Å	sc under pressure Tc=40K	21, 22	
(NH3)4Li3C60	bcc	a=11.843 Å		23	
(NH3)6Na3C60	bcc	a=14.126 Å	localized	24	
(NH3)4Na2Cs C60	fcc	a=14.473 Å	sc Tc=30K	25	
(NH3)xNaK2C60	fcc	a=14.35-14.40 Å	sc 8K<Tc<13K, 0.5<x<1	26	
(NH3)xNaRb2C60	fcc	a=14.50-14.53 Å	sc 8.5K<Tc<17K, 0.5<x<1	26	
(NH3)K3C60	bco	a=14.126 Å	AF below 40K, 
sc under pressure Tc=28K	27, 28,
29	
(NH3)xK3C60	fcc	a=14.32 Å	sc Tc=8.5K, 0<x<1	30	
(NH3)8K3C60	bct	a=12.15 Å, c=15.7 Å		28	
(NH3)xRb3 C60				23	
NaxNy C60	fcc	a=14.204 Å	sc Tc=12K	31	
NaxHy C60	fcc -> s.c.	a=14.356 Å	sc Tc=15K	32	
	tetragonal	a=10.153 Å, c=14.336 Å		33	

x=4
Compounds	structure	lattice parameters	properties	ref.	
Na4C60	monoclinic	a=11.235 Å, b=11.719 Å, 
c=10.276 Å, b=96.16˚	2D-polymer, monomer at T>500K	34,35	
K4C60	bct	a=11.886 Å, c=10.774 Å	semiconducting	36,37	
Rb4C60	bct	a=11.962 Å, c=11.022 Å	semiconducting	36,37	
Cs4C60	bco	a=12.150 Å, b=11.905 Å, c=11.452 Å	semiconducting	36,38	

x=6
Compounds	structure	lattice parameters	properties	ref.	
Na6C60	fcc	a=14.248 Å	semiconducting	14	
K6C60	bcc	a=11.390 Å	semiconducting	39	
Rb6C60	bcc	a=11.548 Å	semiconducting	37	
Cs6C60	bcc	a=11.790 Å	semiconducting	39,37	

x>6
Compounds	structure	lattice parameters	properties	ref.	
Na9.7C60	fcc	a=14.59 Å		40	
Li12C60	fcc -> tetragonal	a=14.09 Å (553K)		41	

Alkaline-earth  metal doped systems

Compounds	structure	lattice parameters	properties	ref.	
Ca2.75C60	orthorhombic	a=27.93 Å, b=28.03 Å, c=27.95 Å		42	
Ca5C60	s.c.	a=14.01 Å	sc Tc=8.4K	43	
Sr3C60	fcc	a=14.144 Å		44	
	A15	a=11.140 Å		44	
Sr4C60	bco		sc Tc=4K	45	
Sr6C60	bcc	a=10.975 Å		44	
Ba3C60	A15	a=11.343 Å		46	
Ba4C60	bco	a=11.610 Å, b=11.234 Å, c=10.882 Å	sc Tc=7.0K	47, 48	
Ba6C60	bcc	a=11.171 Å		49	
CsBa2C60	fcc	a=14.190 Å		50	
K3-xBaxC60	fcc		sc	51	
KBaCsC60	fcc			51	
K3Ba3C60	bcc	a=11.245 Å	sc Tc=5.6K	52	
Rb3Ba3C60	bcc	a=11.338 Å	sc Tc=2.0K	53	
Cs3Ba3C60	bcc	a=11.472 Å		53	
(NH3)8BaC60	rhombohedral	a=12.223 Å, c=21.461 Å		54	

Rare-earth metal doped systems

Compounds	structure	lattice parameters	properties	ref.	
Yb2.75C60	orthorhombic	a=27.87 Å, b=27.98 Å, c=27.87 Å	sc Tc=6K , vacancy ordering	55	
SmxC60	orthorhombic	a=28.17 Å, b=28.07 Å, c=28.27 Å	sc Tc=8K, x~3	56	
Sm6C60	bcc	a=10.890 Å	metallic		
EuxC60			x=3, 6	57	
LaxC60			sc Tc=12.5K	58	

(2) Superconducting Properties

Pressure and magnetic field effects

Parameter	K3C60	Rb3C60	reference	
fcc a( Å)	14.253	14.436		
Tc(K)	19.7	30		
(dTc/dP)p=0 (K/GPa)	-7.8	-9.7	59	
Hc1(0)(mT)	13	26, 19	60,61	
Hc2(0)(T)	26,30,29,17.5	34, 55, 76	60, 62, 63, 64	
Jc(106A/cm2)	0.12	1.5	60	
x0(nm)	2.6,3.1,3.4,4.5	2.0, 2.0, 3.0	59, 62, 63, 64	
lL(nm)	240, 480, 600, 800	168, 370, 460, 800, 210	60, 61, 66, 67, 67, 68, 69, 70	
k= lL / x0	92	84, 90		
dHc2/dT (T/K)	-1.34	-3.8	64, 71	
l (nm)	3.1, 1.0	0.9	72	

Superconducting gap

2D/kBTc	material and method	references	
5.2	K3C60 (STM)	73	
5.3	Rb3C60 (STM)	74	
3.0	K3C60 (NMR)	68	
4.1	Rb3C60 (NMR)	68	
3.6	Rb3C60 (mSR)	66	
4.1	Rb3C60 (photoemission)	75	
3.44	K3C60 & Rb3C60 (optical)	69, 70	
2-4	Rb3C60 single crystal	76	
3.2ｱ0.5	Rb2CsC60 polycrystalline (STM)	77	

Isotope effect

a	material and method	references	
0.300.06	K3C60 & Rb3C60, full substitution (99%)	78, 79	
0.8	Rb3C60, partial molecular substitution (50%)	79	
1.40.5	Rb3C60, partial atomic substitution (33%)	80	
1.20.2	K3C60, partial atomic substitution (60%)	81	
20.25	Rb3C60, partial atomic substitution (60%)	81	
1.450.3	Rb3C60, partial atomic substitution 82%)	82	
0.370.05	Rb3C60, partial atomic substitution (10%) and molecular substitution (15%)	83